Sheffield United have confirmed captain Chris Morgan will miss the rest of the season after suffering cruciate ligament damage.
Morgan had only recently returned to first-team duty after a hamstring injury, but hurt his knee during Saturday's 1-0 defeat by Coventry City.
The centre-half underwent scans on the injury on Tuesday and he is now unlikely to be available for the Blades until next season.
Blades boss Gary Speed told the club's official website: "It's a massive blow for both Chris and the club and realistically we won't see him in action again until pre-season training next July.
"The lads we have that can play in the central defender's role will miss his experience and spirit, but I'm sure they will do all in their power to make up for his absence."
Morgan, who signed a new three-year contract at the end of last season, has made over 270 appearances since moving to Bramall Lane from Barnsley in 2003.