Chelsea goalkeeper Petr Cech has had shoulder surgery following the Czech Republic's World Cup exit.
Cech has helped Chelsea to two successive Premiership titles
Cech, 24, was delaying the operation until his country's elimination from the tournament in Germany.
But Chelsea say the two-hour surgery was routine and needed to clear up "minor problems" from last season.
A representative for Cech said: "The operation was successful. Petr feels well and will have a rest and intensive rehabilitation in the following weeks."
Cech, a key man in Chelsea's back-to-back Premiership victories, now faces a race against time to be fit for the start of the new season on 19 August.
A statement on the official Chelsea website said: "Petr will be working with the Chelsea medical staff to be fit as soon as possible."