The Spanish starlet, who played a key role in Los Leones' impressive 2011-12 campaign, has picked up a muscular injury and may sit out La Roja's opening match against JapanAthletic Bilbao attacker Iker Muniain is a serious doubt for Spain's opening game of the Olympic Games against Japan on July 26.
According to the team doctors, the 19-year-old, who did not take part in Spain's 1-0 friendly victory against Mexico on Wednesday, has sustained a minor tear in his right rectus femoris muscle.
He will allegedly need at least four more days to recover from the problem, and it remains unknown whether he be fit to face the Asian side.
"He is not resting and he is taking part in the training sessions, which indicates that he will soon regain full fitness," doctor Pedro Guillen is quoted as saying by AS.
"Anyway, we will run some more tests in Glasgow [where the match against Japan will take place] and then we will decide."
After the match against Japan, Spain will tackle Honduras on July 29 and Morocco on August 1.