Barcelona's Andres Iniesta sits on the pitch after sustaining an injury during their Group H Champions League soccer match against AC Milan at the Nou Camp stadium in Barcelona, Sept 13, 2011. [Photo/Agencies]

Barcelona midfielder Andres Iniesta will be out for around four weeks after he damaged a leg muscle in the holders' Champions League Group H match at home to AC Milan on Tuesday, the Spanish club said.

Iniesta was replaced by Spain team mate Cesc Fabregas shortly before halftime at the Nou Camp, before Barca conceded a stoppage-time goal to draw 2-2 with the seven-times European champions.

"Tests have confirmed that the player suffered damage to the femoral biceps of the left leg," the La Liga club said in a statement on their website (www.fcbarcelona.cat).

"The approximate time he will be out of action is four weeks," they added.

Iniesta joins injured pair Gerard Pique and Alexis Sanchez on the sidelines.