BUFFALO, N.Y. — In just two months time, Amerks head coach Seth Appert has seen drastic improvements in forward Isak Rosen's game — both between his hands and ears.

"He's faster. He looks harder on the puck, and his first step looks like it's got more — either more pop or more assertiveness," Appert said after practice on Thursday ahead of the Sabres' first matchup of the 2022 Prospects Challenge. "So some of it's physical, but I think part of why you train so hard is also what it does to you mentally. That you know you've put the work in, you know you're ready."

Rosen's returned to Sweden after he was drafted to play with Leksands IF, and was eventually loaned to Mora IK in the second-tier league. His season was cut short due to a hand injury, but the forward said his road to recovery was pretty smooth. He battled for bronze alongside Sabres prospect and Swedish teammate Linus Sjodin at World Juniors in August.

"When I came in at World Juniors, I hadn't played in like four months or something," Rosen said. "So I was pumped up to play again. Coming in with confidence, I played a good first game and just built on that. I'm just trying to continue to build on that."

“He has explosive acceleration. He does it very effortlessly, so his skating is special," Appert said. "He has very good creativity with his vision, but he is a bit of a goal-scorer, which is great to see for a young player.

"I told him yesterday as well, good on him because of how much better he looks now than he did two months ago, and that's a credit to his work. I said it to him and you can see he was smiling. You can tell he knows it. He has put in a ton of work just in the two months since we saw him. And that's why he had a good World Juniors, and that's why he looks better on the ice now than he even did at development camp, which is a good sign."

Rosen's three-year, $4.35M deal currently runs through the 2024-25 season, and may slide an additional year if he does not play at least 10 NHL games with Buffalo this coming season. He impressed scouts ahead of the 2021 Draft with his shifty speed and puck-handling.