Barcelona's 2-0 defeat of Benfica in the Champions League Tuesday came at a high price. Defender and captain Carles Puyol suffered a dislocated left elbow when he fell awkwardly contesting a corner kick and is expected to be out of action for at least a month, which rules him out of the "Clasico" showdown with rival Real Madrid on Sunday.

Puyol, 34, left the field on a stretcher in the 78th minute. He only returned to competitive play this week after suffering a knee injury Sept. 15. His shocked teammates watched in silence as he departed grimacing with intense pain.

"We are waiting for more information but he will certainly miss the clasico," Coach Tito Vilanova told Reuters. The first-year Barca boss is already shorthanded defensively with Puyol's defensive partner Gerard Pique sidelined.

Barca has compiled an eight-point lead atop La Liga in its quest to unseat Real Madrid as champion. "Now we have to forget about the Champions League and have a unique opportunity to do things well at home," said defender Dani Alves. "We know it is going to be a complicated match."