Czech midfielder Vladimir Smicer has been ruled out of the World Cup finals after failing to recover from a leg injury, the CTK news agency has reported.
The Bordeaux player has been struggling for fitness since injuring a tendon behind his right knee in February.
Smicer was diagnosed with a blood clot in his thigh muscle at the Czech Republic training camp in Austria last week after suffering pain in trining.
Rangers midfielder Libor Sionko is likely to be called up to replace Smicer.
The Czechs begin their World Cup campaign on June 12 against the USA, with further fixtures against Italy and Ghana to follow.