It's a chip on his shoulder, just as prevalent 12 seasons into his NHL career as when he was 17 years old, twice passed over in the Ontario Hockey League draft and facing an uncertain future.
Giroux tries to deny it, but it's obvious as his the ruddy beard.
"I don't think angry is the right word," the center said. "You find motivation, you set goals, you try to achieve them."
Giroux's goal at the moment is trying to get the Flyers into the Stanley Cup Playoffs. After their 6-2 home victory against the Anaheim Ducks on Saturday, they are six points behind the Pittsburgh Penguins for the second wild card from the Eastern Conference.
"One game at a time, that's the mentality that we've been having, that's the mentality we need to have," Giroux said.
That includes a big game like the 2019 Coors Light NHL Stadium Series against the Penguins at Lincoln Financial Field in Philadelphia on Feb. 23 (8 p.m. ET; NBC, SN360, SN1, TVAS2).
Giroux and the Flyers lost 2-1 in overtime to the Boston Bruins in the 2010 NHL Winter Classic at Fenway Park, lost 3-2 to the New York Rangers in the 2012 Winter Classic at Citizens Bank Park and lost 4-2 to the Penguins in the 2017 Stadium Series at Heinz Field.
The difference for Giroux this time is he's the captain of the host team and the longest-tenured athlete among Philadelphia's teams in the four major professional sports leagues.
"Anytime you play in those kind of games, it's always special," he said. "Haven't had a lot of success in outdoor games. Would be great to have my first win."
Giroux shouldn't be doubted in his quest to overcome obstacles. It's something he's made a habit of doing for most of his time on skates.
Video: EDM@PHI: Giroux wires home nice power-play goal
Giroux was a well-known player in house leagues around Ottawa but was not one of the 300 16-year-olds selected in the 2004 OHL draft.
In 2004-05 he joined Cumberland of the Central Junior Hockey League. He had 40 points (13 goals, 27 assists) in 48 games but missed time late in the season because of mononucleosis.
Giroux's numbers weren't overly impressive, but he did have a fan in Richard Julien, a youth coach in the region and the older brother of current Montreal Canadiens coach Claude Julien.
"I knew him before from playing midget AA, midget AAA, knew a little bit about him," Richard Julien said. "His name came up pretty often as a good player. So we started following him in Cumberland."
Julien reached out to a friend, Andre Chaput, who owned Gatineau of the Quebec Major Junior Hockey League, and encouraged him to see Giroux play.
Chaput agreed and brought along Gatineau's coach, Benoit Groulx.
To put it lightly, Groulx was unimpressed.
"Not a big kid ... average skater, good skills," Groulx said. "We sat there and watched the kid play, and to be honest I was not excited about him. He was OK."
Groulx offered Giroux an invitation to try out at Gatineau's rookie camp. After Giroux wasn't selected in the 2005 OHL draft, his only chance to play top-level junior hockey was as a walk-on with Gatineau.
"I remember that year in the summer I trained really hard," Giroux said. "I knew that was my only chance of being able to play major junior. I wanted to put every chance on my side. ... That was really the first time I started working out and trying to get better at hockey. Before that I just played hockey, enjoyed the game, was a skilled player, didn't really put the work in. But you're a young player, you don't really know much more.
"That summer really helped me grow as a person to get a little stronger and have a little more confidence in myself."
Groulx didn't need long to realize that the Giroux who arrived at rookie camp with Gatineau was much improved from the player he watched that day with Cumberland.
"He stepped on the ice with the other rookies and by far he was the best player out there," Groulx said. "I couldn't believe the difference between March and mid-August. Then the veterans came in and he's one of the best players on the team right away. And he just kept going."
In 2005-06, Giroux led QMJHL rookies with 103 points, was tied for first with 39 goals in 69 games and made the Canadian Hockey League all-rookie team. But it wasn't always easy.
"The first two weeks were hell," Giroux said. "[Groulx] was hard on me like no one was ever hard on me before. He'd stop drills and make me do laps because I wasn't working hard enough. I didn't like him that much at the time because he was hard on me, he called me out on a few things. But now looking back it was probably the best thing that happened to me."
Groulx said that tough love got the most out of Giroux.
"I think he needed an environment to blossom," Groulx said. "He needed a coach to push him, to challenge him to be the best player on the team and one of the best players in the league. To play well in structure, to be tenacious on the ice. He responded well to everything we said."
Groulx said Giroux's attitude was obvious, and he enjoyed watching the ferocity in his young forward's game.
"When I see him playing angry or with a chip on his shoulder, he's at his best," Groulx said. "He wants to dominate, he wants to be better than the guy in front of him. He wants to be a difference maker."
Groulx has spent 13 seasons coaching in the QMJHL and five in the American Hockey League, including the past three with Syracuse, the Tampa Bay Lightning's affiliate. He said Giroux is the best player he's coached.
"Not only the best, but for me the way he would score goals, the passion, the grit, the way he did it, it's never seen from me at that level," Groulx said. "It was like he knew he was the best, he wanted to be a difference maker for his team. ... He was scoring goals, he was the most-liked player on our team. He would score goal after goal for our team, and always a team-first guy."
Giroux believed his success would lead to NHL teams paying attention, and a solid start to the season landed him at No. 72 on NHL Central Scouting's midterm ranking of North American skaters for the 2006 NHL Draft.
"I'm looking through the list of prospects that might get drafted and I'm thinking I might have a chance to get drafted here," he said. "As the season went on and I was on the list, that was basically the biggest motivation for me, that I had a chance to be drafted into the NHL, to keep my career going."
Giroux was No. 38 in the final ranking and met with 24 teams at the NHL Scouting Combine. But he left for the 2006 NHL Draft in Vancouver with no idea of where he would end up.
The Flyers, who had the No. 22 pick in the first round, were very interested.
"It was pretty easy to see what you see today, his competitiveness, strength on the puck," said Flyers president Paul Holmgren, who oversaw Philadelphia's draft as assistant general manager. "Obviously he's a lot bigger now than he was back then. But it was really evident as a young kid."
Holmgren said the Flyers had a group of five players under consideration for their first selection, with Giroux's name at the top. So when he was available, all general manager Bob Clarke had to do was say his name on the stage.
"Walking up there, I said (to Clarke), 'Claude Giroux, Gatineau in the Quebec Major Junior Hockey League. Gatineau, Claude Giroux,'" Holmgren said.
But Clarke got to the podium and said, "Philadelphia selects from Gatineau in the Quebec junior league ..." then turned to ask Holmgren for one final, very public reminder, creating a memorably humorous moment.
Giroux, however, wasn't upset that his future boss forgot his name.
"I was sitting with my parents and I heard Gatineau, and I thought, 'That's me,'" Giroux said. "Then he forgot my name. It was pretty funny at the time."
Few have forgotten Giroux's name since. Against the Vancouver Canucks on Feb. 4, Giroux played his 791st game, passing Brian Propp for third all-time with the Flyers. He is at 793; the only players ahead of him are Clarke (1,144) and Bill Barber (903). With 505 assists, he is second to Clarke (852), and he ranks fourth with 735 points, behind Clarke (1,210), Barber (883), and Propp (849).
Giroux made a lasting memory on Holmgren long before he became a Philadelphia mainstay.
"I remember his first training camp (in 2006), we used to do the two-mile run on the Eastern High School track and I was sitting in the infield in a lawn chair watching guys," Holmgren said. "He had run his race and he killed everybody; I think he lapped a couple guys. Here comes this brash young kid, he sits down across from me, pulls a chair up and says, 'So what are your plans for me this year?'"
The plan was to send Giroux back to Gatineau for more development. He finished fourth in the QMJHL in 2006-07 with 112 points (48 goals, 64 assists) in 63 games.
In 2007-08 he was second in the league with 106 points (38 goals, 68 assists) even though he missed time while helping Canada win the gold medal at the 2008 IIHF World Junior Championship.
He also missed games while making his NHL debut. The Flyers arrived for a road game against the Ottawa Senators on Feb. 19, 2008 missing several players because of injury and illness, and made Giroux an emergency call-up.
"I went to my mom and asked her if she wanted to go watch Ottawa and Philly tomorrow, and she said, 'Sure I wouldn't mind watching that,'" Giroux said. "Then I said, 'Good because I'll be playing.' I called all my buddies one by one. Was a good memory."
Wearing No. 56, Giroux was minus-1 in 9:27 of ice time, mostly at right wing with center Daniel Briere and left wing Scott Hartnell, and was used first in the shootout for Philadelphia in a 3-2 loss. He was minus-1 in 9:42 two nights later in a 3-1 home loss to the San Jose Sharks before heading back to Gatineau.
He returned in time to help Gatineau win the QMJHL championship. Giroux had 51 points (17 goals, 34 assists) in 19 games and was named playoff MVP.
"Being able to see him battle, and that will every single shift, every practice, being at his best, it's something I looked up to and tried to do," said Montreal Canadiens forward Paul Byron, a teammate for two seasons with Gatineau.
"I got to play against some great players, (Kris) Letang, Luc Bourdon, Brad Marchand, guys that were highly touted players from the Q. But [Giroux] was on another level, dominating games against these great players. You knew he could take his game to the next level. You mix that with his drive and his compete and his willingness, you knew he'd be a great NHL player."
Giroux thought he'd be an NHL player at the start of the 2008-09 season. But after what even Giroux called a less-than-impressive training camp, he began the season with the Philadelphia Phantoms of the AHL.
The chip on Giroux's shoulder grew from the blow to the ego, but he sees it now as instrumental to becoming a full-time NHL player later that season.
"Having John Paddock as a coach, he really helped me, played me 25 minutes a game, put me on the penalty kill, power play, everything," Giroux said. "For my game it was the best thing for me. ... He put me at center and he really helped me understand the game as a centerman and I grew as a player and as a center."
Giroux moved into the Flyers lineup full time later in the 2008-09 season. He had 27 points (nine goals, 18 assists) in 42 games, and five points (two goals, three assists) in six games during his first trip to the Stanley Cup Playoffs.
"He spent a couple months [in the AHL] and that was good for him to play against men and have the chance to play a lot," Briere said. "When he came back to us, right away you could tell he was a special player and ready to take the next step and was going to help."
Giroux had 47 points (16 goals, 31 assists) in his first full NHL season in 2009-10 and scored the Flyers' most important goal, beating Rangers goalie Henrik Lundqvist for the game-deciding shootout goal in a 2-1 victory on the final day of the regular season that got the Flyers into the playoffs and started their run to the Stanley Cup Final.
Video: 2010 Cup Final, Game 3: Flyers get back in series
Fourteen months later, on June 23, 2011, the Flyers traded centers Mike Richards and Jeff Carter, opening the door for Giroux to go from supporting performer to leader. Giroux responded by finishing third in the NHL in 2011-12 with 93 points (28 goals, 65 assists).
The Flyers faced the Penguins in the Eastern Conference Quarterfinals. Philadelphia took a 3-0 series lead but lost the next two games. Giroux decided he was going to take over Game 6 from the opening whistle.
"About 10 seconds before the puck dropped, he came over and told me, 'Watch the first shift,'" Briere said. "And what he did, I didn't even know what to say to him."
Giroux belted Penguins center Sidney Crosby with an open-ice check at the Pittsburgh blue line six seconds into the first period. When Penguins forward Steve Sullivan turned the puck over under pressure in his zone, Giroux jumped on it and beat Marc-Andre Fleury with a shot over his blocker to give the Flyers a 1-0 at 32 seconds en route to a series-clinching 5-1 victory.
Peter Laviolette, then the Flyers coach, said there was a reason Giroux was on the ice to start the game.
"When the best player in the world comes up to you and tells you, 'I don't know who you're planning on starting tonight but I want that first shift,' that says everything you need to know about Claude Giroux right there," Laviolette said that night.
Giroux said Laviolette's postgame statement has been overblown over the years, but the coach stands by it.
"I've always known Claude is a fierce competitor," said Laviolette, who coached Giroux for five seasons and is the Nashville Predators coach. "At the time we had lost a couple games and we needed to have a big game and we needed to have a good start. It doesn't surprise me that he would come and [demand to start the game]. I think that he's a brave player and I think he wants the bigger minutes and toughest opportunity. And he looks to thrive in that."
Giroux was named Flyers captain Jan. 15, 2013, and signed an eight-year contract July 5 of that year that runs through 2021-22.
"I'm really honored to be able to wear the C for an organization like the Flyers," Giroux said. "Great captains that were here before, and you see them coming into the room, coming around, see [Clarke] once in a while. To have that responsibility, it's great. You want to be successful at it."
Giroux isn't a loud voice in the locker room, using deeds rather than words to set the tone.
"I feel [Giroux] just goes out there and gets it done any way possible," forward Wayne Simmonds said. "I think when you lead by example it's great for your teammates. You see that and you want to follow that. If your captain is working that hard, why can't you work that hard?"
Giroux lived with Briere during the 2009-10 season and considers him a mentor. And now he's passing along his experience to his younger teammates.
Flyers forward Travis Konecny said Giroux has been instrumental in his development during his three NHL seasons.
"[Giroux] is always going to be the guy that's working the hardest and setting the example for everybody," he said. "He's definitely vocal when he needs to be vocal but you look at what he does day in and day out, his consistency is the way a leader should play. ... Definitely has rubbed off on me. I've tried to be a sponge as much as I can and soak in everything he's teaching me over the years."
St. Louis Blues forward Brayden Schenn, who was a Philadelphia rookie in 2011-12, also credits Giroux for setting an example. "He took me in early on, showed me the way even though he was a young guy yet he was a leader on the hockey team," Schenn said. "I was pretty lucky to be with him early on and he showed me and took care of me at his condo."
Giroux has been productive and durable during his NHL career. Since becoming a full-time player in 2009-10, he's missed 10 games in 10 seasons, and he's fourth among NHL players in that span with 708 points (221 goals, 487 assists), behind Crosby (781 points), Chicago Blackhawks forward Patrick Kane (765) and Washington Capitals forward Alex Ovechkin (763).
Both of those areas were tested during the 2016-17 season. Giroux had surgery May 17, 2016, to repair injuries to his right hip and bilateral lower abdominal muscles. He was expected to need 10-12 weeks to recover but pushed his rehabilitation so he could play for Team Canada at the World Cup of Hockey 2016.
Giroux played all 82 regular-season games, but his 14 goals were the fewest he's scored in a full season, and the 58 points were his second-fewest, after the 47 he had in 2009-10.
It was the third straight season his output decreased. After he had 86 points (28 goals, 58 assists) in 2013-14, he slipped to 73 points (25 goals, 48 assists) in 2014-15, then to 67 points (22 goals, 45 assists) in 2015-16 before bottoming out in 2016-17.
There was a thought that five years after his coach called him the best player in the world, and with Giroux nearing his 30th birthday, that he no longer was an elite player.
All that did was grow the chip on his shoulder even larger.
"A lot of articles, people talking, that's motivation," he said.
Giroux arrived at training camp in September 2017 healthy, and his teammates could tell something special was in store.
"I saw him skating for 30 seconds and I knew that his stride was better," forward Jakub Voracek said. "That's what made the difference."
Giroux was shifted to left wing, a position he had never played, and finished second in the NHL to Edmonton Oilers center Connor McDavid with 102 points. He also tied Winnipeg Jets forward Blake Wheeler for the NHL lead with 68 assists and was fourth in voting for the Hart Trophy as League MVP.
"I think he's got the best vision and the best hands in the League," Byron said. "The way he can slow down a game and control it, it seems like he's got the puck on this stick the whole game. He sees people out of the corner of his eye and makes passes and you say, 'Wow, how did he even see that guy was open?' And it's a perfect pass, flat, crisp."
Video: PHI@TBL: Giroux dazzles with spectacular goal
Giroux leads the Flyers with 58 points (16 goals, 42 assists) in 55 games this season.
He's also led them through turbulent times of late; this season there's been a general manager change, a coaching change and an NHL record-tying seven starting goalies.
"When it's not going your way it's important you don't get away from what works for you, what you bring to the team, will help the team," he said. "If you try to do someone's job that's not really your job to do, that's when [stuff] hits the fan a little bit. … You have to be able to focus on your game and not try and change your game because it's not working."
Things have been working well recently for the Flyers, including an eight-game winning streak from Jan. 14-Feb. 7 that helped them climb into playoff contention.
For all of Giroux's accomplishments, he wants to help the Flyers to their first Stanley Cup championship since 1975. Watching the Philadelphia Eagles celebrate a Super Bowl championship last February, and a World Series parade for the Philadelphia Phillies in 2008, provides even more inspiration.
"This is a proud city," he said. "Being able to see a couple parades and see teams win the championships and how the city goes behind them, it's definitely motivation that you want to be part of. We know it's not going to be easy but we're going to give everything we have."
It's hard to doubt Giroux, who has made a career out of conquering obstacles and proving doubters wrong.
NHL.com correspondent Sean Farrell contributed to this report