He returned to the ice on Monday morning, but away from the main groups as he skated with fellow injured Leaf Pierre Engvall. Following practice on Monday, Keefe spoke about Muzzin's injury.
"There were a couple of little things that were bugging him leading up to camp that really weren't prevalent all summer long. But as things ramped up there were a couple of things that were on his radar, but he was feeling good enough to go. But now, not so much. Its not related to anything he went through last season, just something he's dealing with right now."
Reading between the lines, it sounds like Muzzin could spend time in and out of the lineup this season if his back continuously flares up - and that's not a good thing. When healthy, like he was against Tampa in the playoffs last year, he is the Leafs' best defenseman not named Morgan Rielly. Hopefully its something the team can get under control and Muzzin is able to work through this season.