Barcelona striker Robert Lewandowski to miss El Clasico with hamstring injury

The 34-year-old has enjoyed a prolific first season with the Catalan giants following his summer transfer from Bayern Munich, netting 25 goals in 31 appearances across all competitions.

Lewandowski was hoping to add to his goal tally on Sunday but he strained his hamstring in the shock 1-0 defeat in La Liga away against Almeria.

Barcelona have sine confirmed the striker's injury on their official website, but they have offered no timeframe on his return to first-team action.

A statement read: "Robert Lewandowski has strained the biceps femoris in his left hamstring. The Polish striker is unavailable until the problem clears up."

The news of Lewandowski's injury comes as a major blow for head coach Xavi, who is already having to cope without injured trio Ousmane Dembele, Pedri and Ansu Fati ahead of Thursday's clash with Real Madrid.

Dembele has not featured for Barcelona since picking up a thigh problem against Girona at the end of January, while Pedri tweaked his hamstring in the first leg of their Europa League playoff against Manchester United earlier this month.

Fati, meanwhile, sustained a knee injury in training prior to Sunday's defeat at Almeria and there is currently no timeframe on his return to the first team.

Barca are now limited for options in attack, with Ferran Torres the most likely candidate to start as the central striker against Los Blancos in Lewandowski's absence.

The Catalan giants are seeking to avoid a third successive defeat when they lock horns with Real Madrid for the first leg of their Copa del Rey semi-final at the Santiago Bernabeu, with Xavi hoping to see vast improvements from his side following Sunday's defeat.

"This was our worst match of the season," Xavi told reporters after the lost to Almeria. "It was too difficult. We weren't there. We weren't inside the match. There are no excuses today. We didn't deserve to win and we have to take responsibility. We noticed fatigue today. That's why we did so many rotations. The players were tired and it was clear.

"We want to say sorry to the fans. What we saw today is inexcusable. I don't understand it. I am the person most responsible. We failed. Luckily we have a cushion of points in La Liga. I always said that it was going to be extremely difficult to win it.

"We lacked passion in the first half. In the second half, we tried everything... 3-4-3, [Ronald] Araujo as a striker... Nothing. It wasn't meant to be. It was not enough. There's nothing else to do but self-criticism. We lacked the intensity of Almeria to win the match.

Barca, who currently sit seven points clear at the top of La Liga, could move one step closer to lifting their first Copa del Rey in five years with a El Clasico victory over Real Madrid in the capital.