Maple Leafs president Brendan Shanahan on Tuesday said Mike Babcock's coaching tactics were not "appropriate or acceptable," addressing allegations of mental abuse by the team's former coach for the first time.

"Times are evolving. We have to evolve," Shanahan said at the NHL Board of Governors meeting. "We all came from a certain generation where things occurred to us as players that we just sort of accepted. We all have to do a better job of just creating that kind of work environment on the ice and off the ice."

Matt Stajan retired Tuesday after 14 seasons in the NHL with the Toronto Maple Leafs and Calgary Flames.

The 35-year-old two-way center announced his decision in a statement through the NHL players' union.