Chelsea goalkeeper Petr Cech will miss the start of the new Premier League season after tearing a calf muscle.
The Czech Republic international pulled up in pre-season training on Tuesday and scans have revealed a muscle tear which will keep him sidelined for four weeks.
Chelsea begin the defence of their Premier League title at home to newly-promoted West Bromwich Albion on August 14.
He will definitely miss that game and also the previous weekend's Community Shield meeting with Manchester United at Wembley.
"Scans have shown Petr Cech has torn a calf muscle in his right leg and the goalkeeper is expected to be out for a month," confirmed a club statement.
"Cech suffered the injury in training and is now expected to miss the start of our competitive season, as well as the remainder of our pre-season friendlies, the next of which comes at Ajax on Friday."
The keeper tore the same muscle during the Champions League last-16 first-leg clash against Internazionale in February and was forced to sit out four weeks of the last campaign.