Coach Mike Babcock didn't shelter Matthews on the wing at age 19; he put him at center and let him learn to play with and without the puck. Matthews set Maple Leafs rookie records for goals (40) and points (69) in the regular season, leading NHL rookies in both categories, tying second overall in goals. Then he had four goals in the first round, first among rookies and second overall, and an assist.
"Historic," Kadri said. "That's what he's capable of. He's a great player."
And he's just one of many promising young players. The Maple Leafs had two more among the top four rookie scorers in the regular season (Mitchell Marner and William Nylander) and three more among the top 21 (Connor Brown, Nikita Zaitsev and Zach Hyman). They used another rookie in this series (Kasperi Kapanen) and three more players who had never experienced the playoffs before (Connor Carrick, Martin Marincin and Morgan Rielly).
"You saw right before your eyes guys on the Leafs grow in the playoffs," Capitals coach Barry Trotz said. "Every experience that you have in the playoffs, you grow a little bit. It adds a layer of hardness, a layer of understanding, a layer of will or competitiveness backbone if you will when you have these series."
Babcock said until you've been through the playoffs, you don't know the level of players you have. He said he learned a lot about his team.
He declined to say what he learned. In the aftermath of the loss, it wasn't the time.
One of the biggest challenges Babcock has faced since taking over the Maple Leafs two years ago is raising the standard, and so he doesn't want everyone to be too happy about losing when Toronto was so close to pulling off an upset.
But he said he was really proud of his guys, and he should be.
"It's hard, grinding hockey," Matthews said. "We played the best team in the League. I think we definitely gave them all they could handle. I think we hold our heads up high. It's obviously not the best feeling, but I think we've definitely got to be proud of each other."