Barcelona striker Lionel Messi faces an anxious wait to determine the severity of a thigh injury he picked up during Wednesday's 1-1 draw with Atletico Madrid.
The Argentine international was substituted at half time in the Spanish Super Cup clash, and will now undergo tests.
"Messi has been replaced as a precaution following some discomfort in the back of the left thigh," read a post on Barcelona's Twitter account.
Messi missed the end of last season with a hamstring strain, but it remains unknown whether the new injury is related.
During the match, Neymar headed an equaliser for Barcelona after David Villa had given Atletico the lead with a wonder goal against his former club.