Yeo, who coached the Minnesota Wild from 2011-16, will make his Blues debut against the Toronto Maple Leafs at Scottrade Center on Thursday (9 p.m. ET; FS-MW, TSN4, NHL.TV).
Along with Hitchcock, goalie coach Jim Corsi was fired. Assistant general manager Martin Brodeur, the NHL's all-time leader in victories by a goaltender with 691, and goalie developmental coach Ty Conklin will take over for Corsi.
"It's a decision that [Blues general manager Doug Armstrong] had to make," defenseman Kevin Shattenkirk said. "It's hard. You never want to see that happen to anyone, but it seems like we need to shake things up a bit. We're obviously all very confident in coach Yeo and what he's shown us so far this year. It's going to be a bit of a fresh start for us moving forward, but as players, we have to look at ourselves as players, too. This isn't just a coaching problem. This is something that we have to fix in the locker room."
Captain Alex Pietrangelo said the presence of Yeo on Hitchcock's staff did not make things awkward for the Blues.
"There was no conflict of anything," Pietrangelo said. "Mike has been nothing but professional. He's been here helping [Hitchcock] the best he can. He's been here treating his role like an assistant coach, not like a head coach. He's said that from Day One and he's stuck to that. I'm going to keep saying that whoever thinks that there was a conflict of interest, there wasn't, because I was actually extremely impressed with the way Mike handled the situation. Obviously a unique one, but he was dealing with it in a solid way. None of us ever thought of it any differently."