Mittelstadt's absence came amid his most productive stretch of the season, one that saw him tally seven points (2+5) in 10 games. He practiced on a line with Evan Rodrigues and Sam Reinhart, the latter of whom he had been skating with prior to his injury.
"I just liked the way he was [playing] before he got injured," Housley said. "He was attacking the game. He was playing a 200-foot game, at both ends of the ice. His defense was really solid, and he was contributing offensively. … His game was in a really good place before he got hurt."
Housley has spoken highly of the extra work that Mittelstadt has put in off the ice to avoid the rookie pitfalls that can occur in the dog days of an NHL season. Mittelstadt said the high volume of games on the pro schedule has actually made it easier to establish a daily routine.
Mittelstadt credited his routine with helping him improve as the season has progressed. His 10-game output prior to his injury nearly matched the production of his first 45 games, when he tallied 12 points (6+6).
"I just try to stick with my routines and what I do," he said. "I've been sticking with it all year and I think maybe right away I didn't get the results I wanted, but before I got hurt I started playing better and making some plays.
"... I think it's important you find your routine and you stick with it whether you're playing good or bad. I feel like my routine has been the same for four or five years now and there's certain things I like to do, certain things I don't do. So, stick to your routine and stick with it, I think it usually figures itself out."
Mittelstadt has had the benefit of navigating his rookie year alongside Rasmus Dahlin. The two have lived together throughout the season, with veteran neighbors like Jack Eichel, Sam Reinhart and Jeff Skinner to help out with meals and other aspects of NHL life.
"They've done a really good job," Housley said. "Casey's done a good job of just doing some extra work with his fitness and Dahlin's doing a really good job of watching video and learning from his mistakes, so they don't happen again.
"And then off the ice they've done a good job. They live together, they hold each other accountable to a certain extent when they're away from the rink and take care of their bodies."