Negredo could now spend four weeks on the sidelines as he tries to recover his fitness and his place in the Spain squad for Euro 2012.
According to the RFEF, the injury-prone striker underwent a nuclear magnetic resonance (NMR) scan which showed a tear in the left thigh muscle.
The results of the test will be sent to Sevilla's medical staff who will perform tehe necessary treatment and monitor the injury.
The player has therefore left Spain's training camp and will return to his club. Negredo has failed to make an appearance for the national team since September 2011.
The withdrawal leaves Vicente Del Bosque light on striking options with Fernando Llorente and Roberto Soldado the only out-and-out strikers left in the squad.
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