Stoke defender Danny Higginbotham faces up to six months on the sidelines after suffering a cruciate knee ligament injury.
Higginbotham suffered the setback in the closing stages of the 1-1 home draw against Chelsea on Saturday and will now miss the FA Cup semi-final against Bolton at Wembley.
Stoke boss Tony Pulis told the Sentinel: "It's a rupture and I'm devastated for the kid. It's a big blow for the team because Danny had just come back into the side and was doing so well."
He added: "Hopefully he will return to training by the back end of pre-season but it's hard to be precise right now. We look after our own at this this club, so once he gets over the shock of the injury, Danny knows he will be getting the best possible care and treatment."
Higginbotham, who signed a contract extension until June 2013 five months ago, scored the winner in the quarter-final victory against West Ham.
Pulis added: "He's been such a great servant to the club and is so popular with the fans and with good reason.
"With the back end to the season we've got coming up, it's a really depressing thing to happen."