But those butterflies were entirely different than the ones in the retired forward's stomach on Thursday when he sat behind the net at Bell Centre for his son Cayden's NHL debut.
"Terrible!" Keith joked after the game of his anxiety, having watched his 20-year-old son make 32 saves in the Montreal Canadiens' 3-2 loss to the Colorado Avalanche.
"I have another son, Chayse, who's a forward out in Omaha (at the University of Nebraska-Omaha), and my wife and I can sit and relax and watch his games with no problem. But when it's a goaltender, you just live on the edge of your seat.
Video: Cayden Primeau on his first NHL game
"This was an exciting game but very nerve-wracking at the same time. Cayden put in a solid performance. I know him; he won't be happy with not getting a win, but it was a good start."
Keith had flown into Montreal on Thursday morning from Philadelphia, from home in New Jersey, with his wife, Lisa, daughter Kylie, and Cayden's long-time goalie coach, Chris Kanaly, and his wife and son. The six had seats together behind the net that Cayden would defend in the first and third periods.
Cayden Primeau, selected by Montreal in the seventh round (No. 199) in the 2017 NHL Draft, joined the Canadiens on Monday after being called up from their American Hockey League affiliate in Laval. He arrived with 12 games of professional experience, 7-4-1 with Laval with a 2.58 goals-against average, .910 save percentage and one shutout.
Canadiens goalie Cayden Primeau postgame Thursday with his father, former NHL forward Keith Primeau, his sister, Kylie, and mother, Lisa.
Remarkably, he was the first Canadiens goalie in a half-century to make his first NHL start on home ice. The most recent was Phil Myre on Jan. 3, 1970, a 22-save 5-1 victory against the Oakland Seals at the Montreal Forum.
Primeau would become the 89th goalie to play in at least one regular-season or playoff game for the Canadiens in their 110-year history, the 85th since the team joined the NHL in 1917 as a charter franchise. As he met reporters in the dressing room after the game, Cayden stood beneath the Hall of Fame portrait of Georges Vezina, the NHL Canadiens' legendary first goalie.
"Obviously excited and a little bit nervous. I just had to get the first one under the belt," he said. "Super motivated. It's good to see this level at the regular season. A lot of things to take away from this game."
Primeau said he settled into his debut "after the first couple seconds. It was exciting but I just tried to take care of it as any other game. I didn't try to think too much (during the national anthems). I tried to give the team the best opportunity to win. Every play is huge, every goal counts, every goal matters. One save is the difference between 2-0 or 3-0 or 1-0."
The speed of the game, he said, was his biggest adjustment from the AHL to the NHL.
"(Colorado's) top line is really fast," Primeau said of center Nathan MacKinnon, who was flanked by Gabriel Landeskog and Mikko Rantanen.
He got a good look at the jets of Landeskog, the Avalanche captain who was returning to the lineup after missing 16 games with a lower-body injury. Landeskog grabbed a loose puck on his own side of center ice, rushed deep into the Montreal zone and powered past Canadiens defenseman Jeff Petry before cutting toward the front of the net and scoring at 12:57 of the first period to make it 2-0.
Colorado's other goals came from defenseman Ryan Graves, who banged in a rebound from a messy scrum at 6:13 of the first period, and forward Matt Calvert, who converted a shorthanded break at 8:06 of the second.
Studying Primeau from the end of the Canadiens bench was Carey Price, the 647-game Montreal veteran.
"He looked great," Price said. "He looked like he settled into the game nicely. He was calm and composed out there."
Price's NHL debut had come on Oct. 10, 2007, on the road against the Pittsburgh Penguins, a 26-save 3-2 win. That was 22 years to the day after first NHL start, also in Pittsburgh, of Hall of Famer Patrick Roy.
"It's definitely a challenge," Price said of a Canadiens goalie beginning his career on home ice. "It's a good hockey team we played tonight. [Primeau] handled himself really well."
Primeau's first NHL save was with his left pad 2:53 into the first period on a 61-foot wrist shot by Avalanche defenseman Ian Cole. The goalie's father might have kicked out a leg in support.
"When I see Cayden get a first shot, I settle in," Keith Primeau said. "Kylie all day was like, 'I just want to see him get his first shot, get his first shot …' She was really nervous for him as well. Definitely, once it starts you get into it. But it's still nerve-wracking."
Keith Primeau had been in Montreal a week ago, tending to business interests in the city, and he and his wife had driven to Springfield, Massachusetts, on Nov. 30 to see their son play for Laval.
It would be a happy, if brief, reunion at the Canadiens' family lounge Thursday, with Cayden in shorts and a team hoodie. Hugs were exchanged before they posed for a family photo prior to the Canadiens' departure for their game at the New York Rangers on Friday (7 p.m. ET; MSG, RDS, TSN2, NHL.TV).
"We weren't planning to come back to Montreal until next week," Keith Primeau said, he and his wife having been here in September for their son's preseason debut. "But we were back on a plane yesterday and we fly home (Friday) morning."
Then, breathing again: "And we drive back up next week."