West Ham defender Angelo Ogbonna looks set to miss the rest of the season after damaging his anterior cruciate ligament.
Ogbonna, 33, will undergo surgery after sustaining the knee injury during their Premier League win against Liverpool.
David Moyes said he expects the Italy centre-back's recovery to take "somewhere around nine months".
"He is going to have surgery, we think surgery will take place over the next couple of days."
Ogbonna was forced off with an eye injury during the first half of their 3-2 victory over the Reds, but later complained of discomfort in his knee.