Barcelona midfielder Andres Iniesta could be out for up to three weeks after injuring his thigh in the King\'s Cup quarter-final second-leg match against Real Madrid, the club said on Thursday. Iniesta sustained the injury in a clash with Alvaro Arbeloa, forcing his departure in the 29th minute. Barcelona went on to draw the match 2-2, winning the tie 4-3 on aggregate.  After being diagnosed with a \"rupture of the femur biceps\" on his left leg, Barca said on their website that Iniesta would be \"out for around three weeks\". Barca\'s progress to the semi-finals of the national cup competition came at a price, with Chilean forward Alexis Sanchez also being sidelined with a shoulder injury.