Tony Mowbray confirmed the blow after the game against Portsmouth on Sunday.
He said: “It is a bad injury. It is a blow to us because he is a threat to most teams he plays against with his size, his power and his strength which puts teams on the back foot.
“He is off to hospital to get a scan and an x-ray to see what the severity of the injury is but the doctors are saying it is medial ligament damage and experience says it will be a minimum of six weeks.”
