He immediately accused his road roommate of cheating, claiming it's been more like two months since Galchenyuk last shaved.
"I'm going to be the worst, I'd expect, in the League," Gallagher said.
The Canadiens' pair of dynamic rookie forwards can indulge in these light-hearted problems only because their play on the ice has been anything but a problem for their team this season.
In fact, it could be argued the emergence of Gallagher, 20, and Galchenyuk, 19, is the biggest reason the Canadiens were able to turn things around so quickly from the nightmare of last season, giving coach Michel Therrien a balanced attack from his forwards that gave opposing coaches matchup problems all season.
The two likely will begin the Canadiens' first-round playoff matchup against the Ottawa Senators playing on either side of center Lars Eller, who at 23 is the grizzled veteran of the line.
The young trio is labeled as Montreal's third line, but none of its members have played like third-liners of late. Eller and Galchenyuk were Montreal's two best forwards in April, with 13 and 12 points, respectively, in 14 games. Gallagher's biggest strength this season has been his consistency, but he had a little burst after being moved onto Eller's line in the team's second-to-last game, getting two goals and an assist in his final two outings.
"We've been playing mostly against other teams' third and fourth lines, I believe," Eller said. "I don't know if other coaches have tried to match lines that hard, but we take whatever comes our way. We don't worry too much about the opposition; it's really about what we're going to do. I truly believe that."
Eller and Galchenyuk have been playing together practically the entire season. Gallagher was the third member of that line early in the season before being moved to a line with Max Pacioretty and David Desharnais before being reunited with Eller during a 4-2 win against the Winnipeg Jets last Thursday.
In terms of total points, Montreal's "third" line was its most productive this season despite the fact Eller and Galchenyuk barely have been used on the power play. Eller set a career high with 30 points, Gallagher had 28 and Galchenyuk 27. When it came to even-strength points, Galchenyuk was second on the Canadiens with 26, Eller third at 25 and Gallagher fourth at 24.
"We're young, we've got a lot of energy and we're just trying to translate it to the ice and get the momentum going for our team," Galchenyuk said. "We just need to keep doing that in the playoffs."
The one who has brought the most energy to the team all season, undoubtedly, has been Gallagher.
Listed at 5-foot-9, 178 pounds, Gallagher plays as if he is 6 inches taller and 30 pounds heavier, crashing the net shift after shift and battling far larger defensemen for pucks along the boards -- and coming out with them on his stick more often than not.
Canadiens defenseman P.K. Subban noted how the team would be fine if everyone played like Gallagher. Indeed, his game is tailor-made for the playoffs.
"The good part about my game is it doesn't have to change at all. I can play the same way, and it just makes it that much more fun," Gallagher said, flashing his ever-present smile that drives opponents nuts on the ice but makes him so engaging off it. "I'm going to focus on playing the same way and doing the same thing I've always done. That said, in the playoffs everything matters that much more. I'm looking forward to it."
As for Galchenyuk, his game has been more of a work in progress all season as he adjusted to the speed and strength of NHL players. Gallagher had the advantage of spending the lockout playing in the American Hockey League, but Galchenyuk jumped to the Canadiens after starting the season with his junior team, the Sarnia Sting of the Ontario Hockey League, then helping the United States win the gold medal at the 2013 IIHF World Junior Championship.
With his 33 OHL games, seven at the WJC and 48 games with the Canadiens, Galchenyuk's 88 games played this season is by far the most of his career -- and significantly more than the eight he played last season (six in the OHL playoffs) following a preseason knee injury.
"I think if I shaved before the playoffs, even if we go really far, there won't be anything on me. So I'm probably not going to shave." -- Canadiens rookie Alex Galchenyuk on his potential playoff beard
Except rather than fade down the stretch, Galchenyuk got stronger.
"I think I just felt more comfortable and adjusted to the speed of the game," Galchenyuk said. "I'm just trying to go out there and be the player I can be and create offense."
Therrien deserves a good deal of credit for how he managed the integration of Galchenyuk and Gallagher into the NHL, and he's doing the same thing again late in the season with the addition of rookie defenseman Jarred Tinordi to the Canadiens' top six on the blue line. However, the coach said it is the team's makeup that deserves the most credit, with a healthy mix of youth, young veterans Subban, Pacioretty and Josh Gorges, and older veterans Brian Gionta and Andrei Markov to help guide the kids along the way.
"I like the chemistry of our team," Therrien said. "We have some good veterans who are taking care of those young kids, and we've got some great young kids with great work habits who listen to veterans, listen to coaches. I believe that chemistry is very important to a hockey team, and our team has that.
"I believe chemistry brought us to where we are right now."
And the final, missing ingredients to that chemistry were two young forwards who have performed so well on the ice that their biggest concern heading into the biggest tournament of their lives is facial hair.