Barcelona's defensive dilemma

Ahead of the third match between his Real Madrid side and Barcelona in less than two weeks, José Mourinho told a press conference that he does not possess a "magic potion" to defeat the capital club's archrival, although he did so in the King's Cup final last week having held the Liga leader to a 1-1 tie four days previously. Much of the reason Real was able to first break a run of five consecutive defeats to Pep Guardiola's swashbuckling side, and then go one better to record a first win over Barça since 2008, lay in Mourinho's tactical blueprint of a three-man protective shield in front of the back four. For Real, preventing Barça from settling into its passing rhythm and denying Leo Messi the space in which he revels proved decisive: defense was the best form of attack.

As the two teams prepare to challenge each other for a place in the Champions League final (8.45pm, regional stattions), Barça faces a different form of defensive conundrum. Guardiola possesses one of the smallest first-team squads among Europe's elite names with a 20-strong contingent backed by the occasional inclusion of players registered to Barcelona B, such as Thiago Alcântara and Andreu Fontás.

Thus Guardiola's squad for the first leg features three reserve team players - defender Sergi Roberto and Martín Montoya, plus midfielder Thiago - to cover the absence of Éric Abidal, who is recovering from surgery to remove a liver tumor, Maxwell, and Adriano, both of whom are injured. Fóntas was drafted into the first team squad in March to replace Abidal, who will not play again this season, but he has made just five senior appearances and is unlikely to be thrown into a game of this magnitude.

It is a problem Guardiola has become familiar with this season. After the World Cup, in the first competitive match of the season against Sevilla in the Spanish Supercup, the Barça coach fielded Dani Alves, Sergi Gómez, Gabi Milito and Abidal in defense. Sevilla won the match 3-1. In the return match Alves and Maxwell played at full-back with Gerard Piqué and Abidal in the center. Barça won 4-0. In club captain Carles Puyol's absence, and with those personnel fit, the formation is the norm. But Guardiola has been forced to field 12 different players in 31 defensive combinations throughout the season.

The Barça mantra is "the better we attack, the better we defend," and whatever the combination at the back, the team's tactic of closing down the opposition and winning back the ball when not in possession is unaltered whoever happens to be playing. It is a proven system: in 27 of Barça's 54 matches this season Víctor Valdés has not needed to pluck the ball from his net. In the league, Barça has conceded just 17 goals in 33 games, nine fewer than Real's 26. Only two other Liga sides, Villarreal and Sporting, have shipped fewer than 40.

With its first-choice back four of Alves, Piqué, Puyol and Abidal on the field together, Barça has won 15 of 18 matches and conceded just four goals. This wall is not available to Guardiola in the Bernabéu. Milito and Puyol have been included in the squad but neither is fully fit - the captain made a hasty return to the team for the league encounter at the Bernabéu after three months on the sidelines and was stretchered off after an hour. Fortunately, in Sergio Busquets and Javier Mascherano Barça has two players more than able of deputizing in central defense and the Argentina captain will likely reprise that role tonight alongside Piqué, with Puyol at left back and Alves patrolling the right.

Mourinho may not possess a formula for success, but the absence of Barça's best back four is a welcome balm to his designs.