Bad news for Toronto Maple Leafs' fans on Thursday. 

All-Star forward John Tavares who accepted Team Canada's invitation for the World Championships left practice earlier this morning. 

While everybody was hoping it was just precautionary, it could be worse. 

Team Canada head coach Alain Vigneault said Tavares has an upper body injury and will be re-evaluated. 

Vigneault said he wasn't sure of Tavares' status moving forward.

More to come.