Asked about the steps McKenna had taken in this, his second game, from his Maple Leafs debut four days earlier, Toronto coach Jim Hiller replied, "I think we all saw it, didn't we?
"I mean, yeah, he was pretty calm and relaxed. We talked about that after the last game. There were some things he felt, like ‘You know, I didn't quite do this.' It's going to be a process for him to understand and adapt.
"(Still), that was encouraging to be able to come back from Game 1 and show what he did tonight."
Another example of the significant steps he's already taken from those Penn State days, where he admits he did a lot of growing up.
In his first 16 games there he scored just four goals, igniting criticism that he wasn't living up to the hype that had accompanied him when he went from the Canadian Hockey League to the Big Ten school.
After representing Canada at the World Junior Championship in Minneapolis and St. Paul, Minnesota, in late December and early January, he was playing with far more confidence down the stretch. McKenna had 33 points (11 goals, 22 assists) in his final 19 games to finish the season with 51 (15 goals, 36 assists) in 35 games.
The Maple Leafs were impressed enough that they selected him first after winning the NHL Draft Lottery, a memorable night in which the pick was announced by Canadian pop star Justin Bieber. In the days that followed, he threw out the first pitch at a Toronto Blue Jays game and attended a World Cup game.
Perhaps his biggest accomplishment during the offseason, he admits, is the improvement in his footwork, something he focused on during on-ice sessions in Vancouver that included young San Jose Sharks star Macklin Celebrini.
"If you asked me if there's one part of his game that caught me off guard, I would say it's his skating," Hiller said. "I don't know if he was talked about that way coming in, but his skating and straightaway speed has been pretty good.
"Of course, we know he's got great agility but that's the thing that's jumped out at me so far."
Even McKenna himself has noticed an improvement in that regard.
"It was a big key for me this summer," he said. "This is a fast league. Guys can really skate in this league. So for me, it's something I pride myself in. I want to be a good skater and be deceptive with it, and I think it helped me out today."
McKenna said he's stoked at the prospect of playing his first regular-season NHL game next Tuesday against the Canadiens at Scotiabank Arena (7 p.m. ET; SN, TVAS) when a number of his friends and family are flying in for the big night. But first comes the trip to Arizona, which he says will bring the team even closer together.
General manager John Chayka feels the same way.
"It's meaningful to Auston. Hometown. This is all to get to know each other better and spend some meaningful time together. And he gets to show the guys where he grew up," Chayka said.
Part of the team bonding will include Matthews hosting the Maple Leafs at his home for dinner.
McKenna, for one, is all in.
"Like I said, it's going to be great," he said. "I'm excited."
Much like Maple Leafs fans were while watching his performance Wednesday.