Timo Glock will not take part in qualifying for the European Grand Prix after feeling unwell due to a stomach ailment.
The Marussia driver had been ill since Thursday but felt well enough to take part in the practice sessions. After Saturday morning's final practice, however, the German fell sick again and it has been decided he will not qualify.
"Timo has been fighting a stomach bug since Thursday," said the team in a statement. "He felt well enough to take part in yesterday's free practice sessions and had seemed to be improving.
"This morning, after free practice three, he started to feel unwell again. It is clear that at this time, he is not sufficiently well to take part in a demanding qualifying session and needs to recuperate further."
Marussia said no decision has been made about Sunday's race.
"Timo and the team will now seek further medical guidance this afternoon. Until such time as this guidance has been received, no decisions will be reached regarding tomorrow's race. A further statement will be issued on Sunday morning."
The team has Maria de Villota as test driver, but she has not driven the car yet.