Celtic captain Scott Brown has sustained an injury during a pre-season friendly between the Scottish champions and Austrian side Rapid Vienna.
The midfielder picked up the knock in the opening minute of the match this afternoon and had to be stretchered off with his upper leg and right knee heavily strapped.
The club later tweeted: "The captain is still being assessed by the club's medical staff and the extent of the injury is not yet known."
The match ended in a 1-1 draw.