Liverpool defender Sebastian Coates is facing a lengthy spell out of action after suffering a knee injury.
The Uruguayan FA confirmed on Tuesday that Coates suffered a torn ligament and will undergo surgery in the coming days.
"In the medical tests, we found out that the player had a torn ligament in his right knee so we have decided to take him to surgery," a statement from the Uruguayan FA read. "It will be done on Friday in Sao Paulo."
If the injury is as serious as feared, Coates is likely to be sidelined until the spring. The defender was signed by Kenny Dalglish for £7 million from Nacional in the summer of 2011, but has played only 12 Premier League games for Liverpool in two years.
He rarely featured during the second half of last season, making only one start after a poor performance in the FA Cup fourth-round defeat at League One side Oldham on January 27.
Coates had been linked with a move to Fulham during the close season, but the chances of selling him in the short term have dwindled.
The injury is set to leave manager Brendan Rodgers short of cover at the back, with Daniel Agger, Kolo Toure and Martin Skrtel the only other players in his squad with significant top-level central defensive experience.
It means Rodgers must decide whether to enter the transfer market for another centre-back before the transfer deadline on September 2.