Chelsea goalkeeper Petr Cech has been ruled out for three to four weeks after sustaining a knee injury in training.
Cech, 29, will miss Premier League games against West Brom, Norwich, Sunderland and Manchester United.
Manager Andre Villas-Boas will have to select from Hilario or Ross Turnbull, given that new signing Thibault Courtois is on loan to Atletico Madrid.
"Cech fell awkwardly with his weight on top of him. We expected much worse when we saw the incident," said Villas-Boas.
He added: "It was the end of training, a normal training incident."