Stoke defender Danny Higginbotham is set to be out for up to six months with a ruptured cruciate knee ligament problem, BBC Radio Stoke understands.
The 32-year-old suffered the injury during Saturday's 1-1 draw against Chelsea and had a scan on Monday.
He will miss the rest of the season, including the FA Cup semi-final against Bolton at Wembley on 17 April.
"It's a big blow because Danny had just come back into the side and was doing so well," said manager Tony Pulis.
Pulis told the Sentinel newspaper: "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 scored the winning goal in Stoke's 2-1 quarter-final win over West Ham in March, signed a contract extension until June 2013 five months ago.
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."