Matthews specifically commented on Penguins captain Sidney Crosby, who helped Pittsburgh repeat as champion by winning his second straight Conn Smythe Trophy, given to the most valuable player of the Stanley Cup Playoffs.
"It's no secret he's the best player in the world for a reason," Matthews said. "Watching, not only him but [Evgeni] Malkin as well, when the Penguins needed a boost or a big play or a lift, it seemed to come from one of those two guys. That exemplifies their leadership and what they mean to that team."
The Penguins defeated the Nashville Predators in six games to win the Cup for the third time with Crosby and Malkin.
Matthews completed his rookie season when Toronto was eliminated by the Washington Capitals in the Eastern Conference First Round. The 19-year-old is often mentioned as the future captain of the Maple Leafs.
"If you want to be the best, those are the kinds of qualities you need," Matthews said. "It's the mindset you want to have to be successful individually but to help the team win as well. [Sidney has] been a pretty good example of that, his leadership qualities, and what he can do on the ice and off the ice as well, and how he is in that locker room."
Matthews, who led NHL rookies with 40 goals and 69 points this season, is a finalist for the Calder Trophy, which will be given to the rookie of the year at the NHL Awards presented by T-Mobile on June 21 (7:30 p.m. ET; NBCSN, SN).