Liverpool are fearing the worst on the fitness of Sotirios Kyrgiakos after the Greece defender was forced off before half-time during his side's 2-1 win over Luxembourg on Wednesday.
Reports in Greece suggest the 30-year-old ruptured his anterior cruciate ligament after colliding with an opponent and will be out for several months.
It will be a blow for Liverpool boss Rafael Benitez, who signed Kyrgiakos from AEK Athens in August as cover following Sami Hyypia's summer departure to Bayer Leverkusen.
The central defender has made just one appearance in the Premier League so far, playing in the 3-2 win at Bolton in August. Since then he has been an unused substitute other than in the Carling Cup game against Leeds.
But the loss of Kyrgiakos leaves Benitez short of cover for first choice centre-backs Jamie Carragher and Martin Skrtel.
Daniel Agger has yet to play for the club this season after coming back from injury, appearing from the bench for the first time in the last Premier League match at Chelsea. It will be a relief that Agger has got two full games under his belt on international duty with Denmark and came back unscathed.
Rookie Spanish defender Daniel Ayala, who made a promising full debut in a 4-0 win over Stoke City at the start of the season, will now be on standby to step up again if the Anfield club suffer any injury or suspension