Tkachuk said that U-18 Worlds was the biggest tournament of their lives at the time.
"For us to go out there and win it was awesome, and to be able to do it with a bunch of guys that are on the team now … it's really fun to come back and play with these guys," he said. "And yes, having that, I guess, winning experience with them, it makes it a lot more fun and a lot more comfortable."
McAvoy, Matthews and Tkachuk now have a chance to lead the United States to its first title in a best-on-best tournament since the 1996 World Cup of Hockey.
The United States leads the 4 Nations Face-Off standings with three points after a 6-1 win against Finland on Thursday. Canada is second with two points after a 4-3 overtime win against Sweden on Wednesday. The rivals meet at Bell Centre on Saturday (8 p.m. ET; ABC, ESPN+, SN, TVAS).
Each team plays three round-robin games, earning three points for a win in regulation, two points for win in overtime or a shootout, one point for a loss in OT or a shootout, and none for a loss in regulation. The top two will play in the championship game at TD Garden in Boston on Feb. 20.
"It's not hard for me to see how the U.S. could lean on those three guys a decade later," said Don Granato, who coached them at the NTDP and the U-18 Worlds. "You could see it back then. You knew they were special players, and they were for me at that time."
You need to understand how the NTDP program works and what the U-18 Worlds means.
USA Hockey selects top players from around the United States for the NTDP, which was based in Ann Arbor, Michigan, and now is in Plymouth, Michigan. McAvoy, Matthews and Tkachuk each spent two seasons there, from 2013-15, training on the ice and off, playing tough competition at home and abroad.
The ultimate goal is to develop for the NHL and top international competition. The immediate goal is to win the U-18 Worlds.
"You're there to win that tournament, and they remind you every step of the way," McAvoy said.
The United States won the tournament in 2014 in Finland. Matthews was on that team. So were four others who are playing for the U.S. in the 4 Nations Face-Off: defenseman Noah Hanifin and forwards Jack Eichel, Kyle Connor and Dylan Larkin.
"You're just thinking, 'Next year I've got to win that tournament,' so there’s a lot of pressure," McAvoy said. "You're almost, like, two years with an eye on a watch, like, 'OK, that tournament's 10 months away …' 'It’s eight months away …'
"And then we went over there, and you're ready."
Granato made sure they were ready, challenging his leaders because he knew that they could take it and that it would help them grow.
"Those three guys were absolute leaders, because they had confidence that their peers didn't," he said. "Confidence in their ability and their ability to succeed. They did separate themselves by the U-18 year in that regard. … They were guys I could really lean on hard and knew they would not fold. They would rise."
In the last international event before the U-18 Worlds, Granato picked on McAvoy on purpose. McAvoy was going to be the United States' go-to defenseman. The team would need him to elevate.
"I remember getting on him for everything, every little pass," Granato said. "Pass in a guy's feet, I'd challenge him on the bench. 'Hey! Is that good enough? You just put it in his feet! He took a hit because you put it in his feet!' Between periods, I had an assistant show him video of what I was yelling at him about, so he'd see it."
It was hard. It was supposed to be.
"He just kept giving it to me, and I remember how much it hurt," McAvoy said. "Like, I was sad, down. But I responded. I played really well. … He was a hell of a coach. I loved playing for Donnie."
The U.S. lost 3-1 to Russia in the opening game of the U-18 Worlds, then went 6-0-0 the rest of the tournament, outscoring the opposition 45-10.
In the quarterfinals against the Czech Republic, the line of Matthews, Tkachuk and Jack Roslovic messed up a 3-on-0 by overpassing. Granato barked at them when they got back to the bench and sat them for a shift.