Barcelona's Javier Mascherano has urged his team-mates to forget next weekend's clásico against Real Madrid and think only of Chelsea before the Champions League tie at Stamford Bridge on Wednesday.

The Catalans beat Levante 2-1 on Saturday night after two goals from Lionel Messi to stay four points behind Real Madrid, whom they face at Camp Nou this Saturday. Mascherano, however, is not giving the Real match any thought.

"We want to put the league out of our minds a bit and focus on Chelsea because we have the chance of reaching the final of Europe's top competition," the Argentinian told the Barcelona website .

"It'll be a really difficult tie that will depend a lot on getting a good result in the first leg [at Stamford Bridge] against a team that has always been characterised by their tremendous physical strength and which has some really experienced players."

Mascherano, who was part of the Liverpool team that defeated Chelsea in the 2006-07 semi-finals but went on to lose the final against Milan, added: "The main thing right now is Wednesday's match. Afterwards we'll think about the league and Real Madrid. We're in a Champions League semi-final and we have a great opportunity to reach the final. It would be a really big mistake to focus on Real Madrid first, because Wednesday's match is very difficult and will go a long way to deciding the tie."

Barcelona have won 14 out of their past 15 games, the only draw coming in the away leg of the Champions League quarter-finals against Milan, and Messi has now, remarkably, scored 24 goals in his past 13 games. Mascherano, however, does not believe Barça are over-reliant on his international team-mate.

"We know that we have a player who usually gives us at least one goal or the final pass for other players," Mascherano said. "Messi makes the difference and having the best player in the world in your team means you tend to depend a bit on him because he's goal-hungry and it's very possible that in any match he can be the deciding element. But you have to say that sometimes it's the goals of Cesc [Fábregas], Xavi, Alexis [Sánchez] or [Andrés] Iniesta that have kept us alive."

The Barcelona coach, Pep Guardiola, has no new injury concerns after the win at Levante and the Dutch forward Ibrahim Afellay, who tore a ligament in his left knee during training in September and has spent nearly seven months regaining his fitness, has rejoined the squad and is available for selection against Chelsea.