As the "The Star-Spangled Banner" played, many in the Bell Centre crowd booed loudly, despite a pre-anthem plea to show respect.
He didn't say whether the anti-American gesture fired him up, but his body language during the anthem -- cameras caught him doing a slow burn on the bench -- and his performance on the ice suggested maybe it did.
Tkachuk scored two goals and set up one of little brother Brady Tkachuk's two tallies in the dominant win.
The booing was the lead story on Canadian news programs Friday morning.
American teams have heard the boos in Canada before, and they picked up in intensity in recent weeks as President Trump suggested the possibility of annexing Canada as the 51st state. In addition, Trump this week ordered a 25 percent tariff on imports of steel and aluminum into the US from all countries, including Canada.
The NHL was aware the boo birds might flock to the Bell. When Trump delayed by 30 days his plan to assess a 25 percent tariff on all Canadian goods, the hope was booing wouldn't be an issue, but that was not the case.
"It's unfortunate, obviously, and we wish it wasn't the case," NHL deputy commissioner Bill Daly said during a joint news conference with the NHL Players Association this week. "But from time to time things happen and people have strong feelings about it. Obviously, we're aware of what's been happening here."
Team USA coach Mike Sullivan wasn't sure if the anti-American gesture galvanized his team, but he was passionate when addressing the issue.
"Here's what I'll tell you: These guys are hockey players and they're here to play hockey. They're also proud Americans. And it's a privilege to represent your nation and all of us that have the opportunity to participate and be part of this US team," said Sullivan. "It means a lot to all of us, and to represent our nation is something that we think is bigger than ourselves, or the sport for that matter. So, from that regard, I think we have guys that are proud Americans. As far as the national anthem, I'm not sure there's influence there. That's really not something that we can control. We just want to play hockey, we want to compete, we want to represent our nation in the right way."
American forward J.T. Miller believed the booing served as extra motivation.
"I think we liked it," he said. "Not politically, but maybe just as a sense of, we know where we're at in Canada and I think that fires us up more than anything. So, it's great."
Team USA will next face Canada Saturday night. The boys in red, white, and blue likely will hear boos again, but Canadian Brad Marchand hopes they don't.
"For me, anthems are to pay respect for the veterans that give their lives so that we have freedom," said the Bruins' captain. "So, I think that people should respect anthems at all times. Otherwise, you're disrespecting millions and millions and millions of people that literally gave up everything so that we can have our freedom. I don't think that's appropriate, but everyone's free to do their own thing."
Elias Lindholm, who will be part of the third line for Sweden's game Saturday against Finland, said everyone in the Bruins' locker room knows what's at stake in the crowded Eastern Conference playoff race.
The Bruins lost their final two games before the break, despite having leads in both, against the Rangers and Golden Knights.
"Everyone was disappointed. I think we know it's going to be a dogfight until [the end of the season]. We kind of threw away the last two games, 2, 3, maybe 4 points, which was disappointing," said Lindholm. "[Coach] Joe [Sacco] is one of those guys that doesn't say too much after the games. He just said, 'Enjoy the break.' And everyone knows that we're going to have to win a lot of games to get back from this. So, I think everyone deep down knows what's going to happen and what we're about to face. A lot of guys were [ticked], but now we have a break and we'll be ready when we get back."
The Bruins will get back to practice on Tuesday, with their next game Feb. 22 against the Ducks.
Canadian defenseman Cale Makar missed Friday's practice because of an illness. The club has summoned Thomas Harley to Montreal in case Makar, the former UMass star, can't play Saturday night ... The Americans' win over Finland snapped a five-game skid in best-on-best competition. Team USA went 0-3 at the 2016 World Cup (losses to the Czechs, Canada, and Team Europe) and lost its final two games at the 2014 Sochi Olympics, to Canada in the semifinals and Finland in the bronze medal game ... A win over Canada would put the Americans in the 4 Nations Face-Off title game Thursday at TD Garden, regardless of what happens Monday against Sweden ... The 4 Nations Face-Off Fan Village shifts to Boston City Hall Plaza Saturday from 11 a.m.-6 p.m. Fans can enjoy hockey-themed games, interactions with special guests, and get a glimpse of the 4 Nations Face-Off championship trophy and the Stanley Cup. No tickets are needed for the Fan Village, which runs through Monday.