Montreal Canadiens forward Rene Bourque will be out indefinitely with a concussion.

Coach Michel Therrien said Tuesday that Bourque is not sure what caused the injury. He missed the last two games with what the team said was a flu.

Bourque had five goals and five assists in 17 games and was playing well on a line with Tomas Plekanec and Brian Gionta. Brandon Prust has taken Bourque's spot on the line.

The Canadiens face the Maple Leafs in Toronto on Wednesday night.