Chelsea have been rocked by the loss of goalkeeper Petr Cech for a month.
Cech injured his calf in training on Tuesday and scans revealed a small tear.
Cech will miss the rest of the club's pre-season programme and is unlikely to feature in the Community Shield against Manchester United at Wembley on August 8.
A spokesman for Chelsea confirmed: "Petr will be out for around a month after scans showed a tear in his right calf. He is expected to miss the rest of the pre-season campaign."