Vlasic (undisclosed) was placed on injured reserve Sunday, per the NHL's official media site.
Vlasic's placement on IR is retroactive to Jan. 2, so he could still return for Monday's game versus the Panthers, although it's unlikely. This will open up a roster spot for the Sharks to possibly recall a depth defenseman if Erik Karlsson (undisclosed) is unable to shake his injury by Monday's contest.