The Leafs and Bruins are playing Monday night in their third meeting of the year, but all of the talk in the Air Canada Centre dressing rooms is about another game taking place two hours down the road.
The U.S. against Canada at the world junior hockey championship in Buffalo, a must-win semi-final where the winner earns the right to play for gold on Wednesday.
Bruins forward Brad Marchand, who played for Canada in the tournament twice and won gold in 2007 and 2008, believes the U.S.-Canada rivalry is now the top one in international hockey.
"I think it's a hatred," Marchand said. "Obviously you want to respect your opponent at the end of the day, but when it's out there [on the ice] you want to tear their heads off.
"You want to make them look bad and you want to hurt them and you want to embarrass them. It's definitely hatred. You're playing for your country."
Leafs coach Ron Wilson disagreed, saying the rivalry was one of "respect."
"There's no hatred," he said. "There's great respect. All the players are intermingled, whether Canadian kids are playing college hockey, American kids are playing junior hockey. They're teammates and then they have to face each other in these situations.
"It's a great rivalry. It's too bad that we have to play tonight, that we can't sit around and watch the game. I wish it was for the gold medal. I wish that Canada had won that game against Sweden so that it would have setup a potential Canada-U.S. final, but it's not to be."
Leafs winger Phil Kessel said his experience playing Canada has generally been a losing one, as his American teams finished fourth in his two trips to the world juniors and lost in the final at the 2010 Olympics.
"Obviously it's a big rivalry," Kessel said. "A lot of guys know each other on the other team. I think the building tonight there will be rocking. It should be a fun game."
Bruins teammates Blake Wheeler and Milan Lucic, sitting beside one another in the dressing room, joked that their friendship was on the line as part of a wager on the game.
Wheeler skated for the U.S. at the 2006 tournament, while Lucic was in the NHL at 19 and has little international experience.
"There's definitely a lot on the line," Lucic said. "Goaltending, that's what it is for us. When we get the right goaltending, we should be fine."
Both players recalled how they were in Ottawa for a game against the Senators during last year's gold-medal final, when the U.S. beat Canada 6-5 in overtime.
The crowd stayed in the stands after the Bruins' 4-1 win to watch the juniors play on the jumbotron while the players watched the end of the game on the bus.
"The U.S. got the last laugh in that one and hopefully it'll be different this time around," Lucic said. "We've got to let them win sometimes and make them feel good about themselves."
Wilson was asked to compare the world junior event to his experience at the Olympics as coach of the American team.
"I hate to tell the people from TSN, I don't think the whole world is watching this," Wilson said. "It's a junior championship, but these kids will play with passion.
"The U.S. is the defending champion, playing on home soil, but if they do fill the building tonight, I suspect that two-thirds will be Canadian and a pro-Canadian crowd so the U.S. is going to have their hands full. The Canadians will be really motivated because of what happened last year."
Marchand said the pressure on Team Canada, even while playing in Buffalo, is immense.
"If Canada loses a game, the whole nation's disappointed," he said. "You have so much pride. There's so much pressure. You want to be the best, you want to be the guy out there against the Americans and you want to dominate them.
"You can't explain it. It's a feeling that you have to be in the room and around the guys to really understand, but it's something you really want to be a part of. It's amazing when you come out on top."