Martin St. Louis announced his retirement from the NHL on Thursday after 16 seasons.

The undrafted forward struggled at the beginning of his career with the Calgary Flames before establishing himself with the Tampa Bay Lightning.

St. Louis had 391 goals and 642 assists (1,033 points) in 1,134 regular season games in the NHL, and won the Stanley Cup, two Art Ross trophies and three Lady Byng trophies.

Here are some highlights from St. Louis' NHL career:

Nearly two decades later, Craig Ramsay still remembers the smallest player on the ice at the start of Ottawa Senators training camp in 1997.

Ramsay was an assistant coach, and there among Alexei Yashin, Daniel Alfredsson, Vinny Prospal and Alexandre Daigle, was this pint-sized, undrafted training-camp invitee speeding all over the ice. Before Ramsay could figure out who he was, however, he wasn't there anymore.

"I never had a chance to work with him other than to notice him because he was pretty noticeable," Ramsay told NHL.com. "He was a nifty, small guy. And then he was gone."

Martin St. Louis was gone from that Ottawa camp, but after a 16-season career that is likely to include induction into the Hockey Hall of Fame, he won't soon be forgotten.

Phil Kessel hasn't missed a game five seasons, but he always felt like they ended too early. He expects that is about to change.

The nine-year veteran spent the past six seasons with the Toronto Maple Leafs before he was traded to the Pittsburgh Penguins on Wednesday.

"Being in Toronto, I got to play in one playoffs in all my years there," Kessel told reporter Dejan Kovacevic on Thursday. "But that's the best time of the year, right? Playoff hockey. Hopefully, I'll get to play in many in Pittsburgh."

Philadelphia Flyers general manager Ron Hextall wasn't very active the first day of NHL free agency Wednesday, because of salary-cap constraints and by choice.

Although help on the wings and more mobility on defense are offseason needs, the Flyers' only significant signing was backup goaltender Michal Neuvirth. Terms weren't released, but Sportsnet reported the two-year contract will pay Neuvirth $1.5 million in 2015-16 and $1.75 million in 2016-17.

The Flyers have about $5 million left under the $71.4 million NHL salary cap, according to war-on-ice.com, and that doesn't include a contract for restricted free agent defenseman Michael Del Zotto.

The only new forward is Sam Gagner, acquired from the Arizona Coyotes on June 27 in a trade for defenseman Nicklas Grossmann and the contract of defenseman Chris Pronger.

DETROIT -- Coach Jeff Blashill says the signings of defenseman Mike Green and center Brad Richards provide the Detroit Red Wings with more flexibility.

"I think, in a lot of ways, they give us more options," Blashill said Thursday. "We think they fit in with our team and bring some unique skills."

The Red Wings signed Green to a three-year contract and Richards to a one-year contract Wednesday, the first day of NHL free agency. Green's contract is worth $18 million, and Richards is guaranteed $3 million for the 2015-16 season but could make $4 million with bonuses, according to TSN.

Blashill is going into his first season as Red Wings coach after replacing Mike Babcock, who left Detroit after 10 seasons to coach the Toronto Maple Leafs.

The Vancouver Canucks ran out of patience with Zack Kassian. The Montreal Canadiens hope to benefit from that lack of patience.

The Canucks traded Kassian, the 13th player taken in the 2009 NHL Draft, and a fifth-round pick in 2016 to the Canadiens on Wednesday for forward Brandon Prust, ending a tumultuous four seasons in Vancouver for the hulking right wing.

Canucks general manager Jim Benning explained that he wanted to add toughness and consistency to his lineup by replacing Kassian with Prust, who is seven years older and carries a salary-cap charge that is $750,000 more than Kassian's.

CALGARY -- General manager Brad Treliving knows the Calgary Flames' on-ice success last season, when they qualified for the Stanley Cup Playoffs for the first time since 2009 and advanced beyond the first round for the first time since 2004, will increase expectations on them next season.

So, too, he predicts, will his recent acquisitions.

The Flames signed free agent forward Michael Frolik on Wednesday, five days after adding defenseman Dougie Hamilton in a trade with the Boston Bruins then signing him. Calgary also retained goalie Karri Ramo, re-signing him before he hit the free agent market.

"We told our team this, at the locker clean-out I said, 'We all have to be better, and it starts with me,'" Treliving said. "What we accomplished last year was nice, but ultimately it's just a step. The fact we had the season we had is going to raise expectations. That's just human nature, and we can't shy away from those. If we all want to be good, this is what happens. There's more expected. There's more pressure. We've got to start living like a team that wants to be good.

"I think those expectations are a good thing. That means you've added good people. The people you do have have had some success, so there should be expectations."

PITTSBURGH -- Pittsburgh Penguins general manager Jim Rutherford did what he said he would.

Rutherford declared after Pittsburgh was eliminated from the Stanley Cup Playoffs in five games that he would bring in at least one top-six wing. He did just that Wednesday, when the Penguins acquired forward Phil Kessel from the Toronto Maple Leafs.

"I'm very excited about what happened today," Rutherford said. "We've worked on this deal with Toronto for a month, or over a month. It got a little bit of legs on draft day, but it really heated up last night, and we were able to complete the deal today.

"We set out this offseason to bring in more skill on the wing and some more speed. I certainly think we covered that by adding Phil Kessel. We also liked to get some consistency of wingers for [Evgeni Malkin] and [Sidney Crosby]."

TORONTO -- The Toronto Maple Leafs continue to add youth and skill to their roster with the additions Wednesday of forwards Kasperi Kapanen and Nick Spaling and defenseman Scott Harrington from the Pittsburgh Penguins in the Phil Kessel trade.

Kapanen, whose father Sami Kapanen played 831 NHL games scoring 189 goals and 458 points, is another young player the Maple Leafs hope will develop into a top-six forward.

"He's one of the youngest players that was drafted two years ago," Maple Leafs president Brendan Shanahan said. "He came over this year and played a little bit in the [American Hockey League]. He's a talented guy; a top-six forward, we are hoping. I think he adds to another group of players that we have in our stable, that with a lot of work and a lot of patience and some development, we hope he can become a very productive Leaf at some point."

TORONTO -- The Toronto Maple Leafs' new direction continued Wednesday with the trade of veteran right wing Phil Kessel to the Pittsburgh Penguins.

Kessel has led the Maple Leafs in scoring the past six seasons, but was traded along with minor-league center Tyler Biggs, defenseman Tim Erixon and a second-round pick in the 2016 NHL Draft for forwards Kasperi Kapanen and Nick Spaling, defenseman Scott Harrington and a first- and third-round draft pick in 2016.

Having not yet hired a general manager, Maple Leafs president Brendan Shanahan orchestrated the trade, which he said started at the draft last week in Florida.

"I had said at the end of the season there were going to be changes," Shanahan said. "For whatever reason we had a lot of talented individuals on this team, but as a group, the core group, it hadn't worked. This is about winning. Phil is certainly a very talented player and we knew changes had to come."