Barcelona defender Eric Abidal is to have a liver transplant, the Spanish and European champions said.
The France international, a cult figure among fans of the Catalan club, had surgery to remove a tumour from the organ last March before making a triumphant return to lift the Champions League trophy at Wembley just two months later.
"Over the coming weeks, the player (Abidal) will undergo a liver transplant," Barca said in a statement on their website (www.fcbarcelona.com).
"The transplant was an option already mentioned since the start of his treatment a year ago," the statement added.
The club did not say how long the 32-year-old would be out of action but his chances of returning before the end of the season and representing France at Euro 2012 starting in June must be in serious doubt.
Abidal's Barca team mates rallied behind him following the announcement, with striker David Villa, himself sidelined with a broken leg, saying they needed him back in the team as soon as possible.
"All my strength for Abidal!" Villa wrote on his Twitter feed. "You will get through it. You are very strong. We will all be by your side," he added.
Central defender Gerard Pique wrote on his feed: "You will return and you will do it like always, being the best! You are an example for everyone."
Barca are losing Abidal at a critical time in the season, with the Champions League holders through to the quarter-finals of Europe's elite club competition and bidding to close a 10-point gap with Real Madrid in La Liga.
They are also will face Athletic Bilbao in May's King's Cup final.
Abidal is likely to be replaced in Barcelona's lineup by Adriano and captain Carles Puyol is also able to fill in at left back.