Barcelona will have to produce one of the all-time European comebacks against Bayern Munich on Wednesday if they are to advance to the final of the Champions League next month.

The German outfit secured a 4-0 win in the first leg last week, meaning that an away goal for Bayern would leave Barcelona needing to score six times at Camp Nou on May 1.

However, Barcelona will take heart from the last time they welcomed Bayern to this stadium in April 2009, with a double from Lionel Messi enough to secure a 4-0 win over their German opponents. That score this time around would take the semi-final clash into extra time.

There is no doubt, however, who enter the match in the stronger form. Barcelona have won just two of their last five matches in all competitions, but they are still 11 points clear at the top of La Liga with five matches remaining.

Bayern, meanwhile, have already secured the Bundesliga title this season, having won 27 of their 31 league matches, losing just once in the process. They will also contest the final of the German Cup against Stuttgart at the beginning of June.

Barcelona could welcome back skipper Carlos Puyol following a long-term absence, but should the Spaniard fail to recover, Alex Song could be drafted into defence alongside Gerard Pique with Javier Mascherano still out of action.

Messi is also certain to start in attack, but Cesc Fabregas and David Villa may once more have to be content with places on the bench.

Bayern, meanwhile, rested a host of players at the weekend, but all are expected to return for the trip to Spain. Mario Mandzukic could be handed the lone striker role in place of Mario Gomez, although the German did score in the first leg. Jerome Boateng is also expected to keep his place in defence, meanwhile, with Daniel van Buyten consigned to the bench.

Recent form:

Barcelona: DWWLD

Bayern: WWWWW

Possible lineups:

Barcelona: Valdes; Alves, Pique, Puyol, Alba; Busquets, Xavi, Iniesta; Sanchez, Messi, Pedro

Bayern: Neuer; Lahm, Dante, Boateng, Alaba; Martinez, Schweinsteiger; Robben, Muller, Ribery; Mandzukic

Sports Mole says: 2-1