Chelsea goalkeeper Petr Cech has been ruled out for three to four weeks after injuring a knee ligament in training.

The injury was announced by manager Andre Villas-Boas at Thursday's news conference.

The Chelsea manager says ''it was the end of training (on Wednesday), a normal training incident. He fell awkwardly with his weight on top of him. We expected much worse when we saw the incident.''

New signing Thibaut Courtois is currently on loan at Atletico Madrid, meaning Ross Turnbull and Hilario will compete for the starting spot against West Bromwich Albion on Saturday.