The two old rivals were to play each other on Tuesday night at the Bell Centre, but there was more to ponder than just hockey.
Gainey remained with his family, dealing with the shock of his 25-year-old daughter Laura gone missing at sea. The air search was called off Monday after more than three fruitless days of scouring a wide swathe of the U.S. Atlantic coast.
Kessel, a rookie centre with star potential, did not make the trip to Montreal with the team on Monday due to what a statement from his family said was an undisclosed "health issue."
His agent Wade Arnott told the Boston Globe on Tuesday that Kessel underwent cancer surgery at Massachusetts General Hospital, without going into detail. A Boston television station reported it was testicular cancer.
Bruins winger Marc Savard said Kessel, usually his roommate on road trips, seemed to be OK, under the circumstances.
"I was one of the fortunate ones to talk to him (Monday) night and he's doing good, so we're happy with that and we can't wait to get him back," said Savard.
"For such a young kid, tough times probably feel tougher. Especially in his first year in the NHL."
The Canadiens got approval from the league to close their dressing room to the media after their game-day skate Tuesday morning. A day earlier, the Gainey story had drawn dozens of reaction-seeking media people to a practice.
Coach Guy Carbonneau said he received a call from Gainey on Tuesday morning thanking the players and team staff for their support.
"He's doing as good as you can expect," said Carbonneau. "This last weekend has been really hard on him.
"It's hard to imagine all the emotion that goes through your mind when they're searching. Since Friday night, I think it's been really hard."
The team released a statement from Gainey and his other children Anna, Steve and Colleen thanking "all the people who have been involved in the search for our darling Laura."
It also thanked their friends and the public for their support.
The statement came with a photograph of Bob and Laura Gainey aboard the tall ship she was working on when she was swept overboard by a large wave during a storm on Friday night.
Carbonneau said he would not bring up the issue with the players before the game. Team president Pierre Boivin and assistant GM Pierre Gauthier had already addressed it with the players on Monday.
"I don't want to make any sensational speeches," added Carbonneau. "I was never like that - to use something like that to motivate players.
"They know what the situation is. Everyone knows it was a difficult weekend, but they're professionals and know what their job is, even though our thoughts aren't there sometimes. The best way to help Bob and his family right now is to continue to play well, work hard and try to win games."
His Bruins counterpart, Dave Lewis, said that for the players, games can be a refuge from emotional shocks away from the ice.
"The players love to play and that's their whole life," said Lewis. "When they get a chance to play, that's their special time. They forget about all the other things that are going on and try to focus on that."
Kessel was drafted fifth overall by Boston in June from the University of Minnesota. The quick and gifted centre from Madison, Wisc., who was used mostly on the fourth line and the second power-play unit, has five goals and four assists in 29 games this season.
The Bruins recalled centre Yan Stastny from AHL Providence to fill in for Kessel.
"He's an important part of our team, but right now, he has to take care of some things," said Stastny. "Health is the most important thing."
It is not known how long Kessel will be out of action. Hope may spring from the fact that testicular cancer, if detected and treated early, has a cure rate of 99 per cent, according to the American Cancer Society.
There is also no word on how much time Gainey will need to deal with his daughter's disappearance.
Boivin and team owner George Gillett released a statement in which they extended their "deepest sympathies" to the Gainey family. It added the club would make no further comment.
"There's two stories going on in the NHL now with our two teams and both situations are really tough," said Bruins forward Brad Boyes. "There's more important things in life than hockey."