Andres Iniesta has been diagnosed with a hamstring injury after being forced off in the second half of Barcelona's 2-1 win over Bayer Leverkusen.
The Spain international signalled to the bench that he would be unable to continue after he went to ground on the 60-minute mark, with Jordi Alba his replacement.
Though able to walk unaided from the pitch, Iniesta was seen punching a dugout chair in frustration as he took his seat, and the club have since confirmed the problem.
"The player has an injury to the femoral biceps of his right leg," a statement released by Barca said.
"His return to training will depend on his progress."
Late goals from Sergi Roberto and Luis Suarez saw Barca come from 1-0 down to secure their first win in Group E.
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