Mittelstadt credited his performance to an eye-opening experience during the prior season, when he was reassigned to Rochester after 31 games. It was the first AHL experience for the forward, who had made an immediate jump to the NHL following his freshman season at the University of Minnesota in 2018.
Mittelstadt took the reassignment in stride and refocused his off-ice efforts, habits that carried over into the elongated offseason.
"It was a good lesson for me to go home and realize the amount of work I have to put in every day, and the things that I have to do away from the rink to get myself ready to play," Mittelstadt said. "I think that was the biggest difference more than anything. I think when you do that, you get in a zone and start playing well. You get out what you put into it."
Mittelstadt spent the beginning of last season working primarily with the taxi squad, appearing in 12 games prior to Granato's appointment as interim head coach on March 17. Granato used the final stretch to provide top-line experience for Mittelstadt, often centering fellow young forwards Rasmus Asplund and Tage Thompson.
Granato was hired as the team's permanent head coach on June 29.
"I think a lot of guys, including myself, owe Donnie quite a bit," Mittelstadt said. "He challenged me when he took over and pushed me to become a better player. I think it's that simple. A lot of the strides I made are partly because of him pushing me or had a lot to do with him pushing me."
With the return of Mittelstadt, the Sabres have two remaining restricted free agents in defensemen Rasmus Dahlin and Henri Jokiharju.