Boulahrouz suffered the injury just before half-time at Stamford Bridge in his first start since recovering from a knee ligament problem that had kept him out for six weeks.

The Dutch international's injury could hardly have come at a worse time as Chelsea prepare for crucial matches against Porto in the Champions League and Arsenal in the League Cup final next week. "Boulahrouz has a dislocated shoulder so he will be out for some time," revealed Chelsea manager Jose Mourinho.

"The only thing not positive was the Boulahrouz injury. If you can forget that, the result was good and we are in the quarter-finals."