Carlo Ancelotti’s Real Madrid side went unbeaten for 31 games, but have now lost twice in the space of four days and now the old debate over the selection of Diego Lopez has started again.

In the space of four days, Real Madrid’s title challenge has careered off the rails after defeat at home to Barcelona and now a loss at Sevilla on Wednesday. These two defeats were also marked by Diego López’s undistinguished performances, which has raised the old questions again about the Real Madrid No1 shirt. The Galician giant has conceded six goals in the last two games and failed to make a real save of note in either match, leading people to wonder whether the time has come to restore Iker Casillas to the starting line-up.

While Sergio Ramos and Cristiano Ronaldo ranted at the referee after the 4-3 loss to Barca, coach Carlo Ancelotti called for an immediate reaction – and for a while he looked like he’d get it. But Karim Benzema was wasteful in front of goal early on and when Madrid did go in front, through a fortuitous free-kick deflected in off the Sevilla wall, their lead lasted only four minutes. Stuff of champions it was not.

Yesterday’s was Sevilla’s sixth straight win. Bacca was in fine goalscoring form and his brace sealed the home side’s comeback after the Portuguese had given Real the lead. Carlo Ancelotti’s side had no answer for Sevilla’s intelligent football and winning La Liga now looks to be an uphill struggle for them. Real Madrid head coach Carlo Ancelotti made only one big change from the starting XI that took the field in last Sunday’s Clásico as Asier Illarramendi replaced Ángel Di María in the midfield.

López could hardly have had a worse return to the Sánchez Pizjuán as Real recorded a second defeat on the bounce, proving unable to conjure up his heroics from earlier in the season to stop Bacca, just days after being powerless to keep out Iniesta and Messi at the Bernabéu.

Lopez looked suspect as Bacca netted what proved to be the winner with 18 minutes left. The Galician goalkeeper made contact with his legs but the ball still ended up in the net. Those saves are bread and butter for Iker Casillas and it would be no surprise to see the skipper back in the team before too long.

This year’s La Liga title race promises to be one of the most exciting finales in history, with just three points separating Los Blancos, Barcelona and Atletico Madrid. At this late stage, the trophy’s destination could be settled by a single moment, and having a top custodian between the sticks is absolutely vital. Since being appointed as Los Blancos head coach last summer, Carlo Ancelotti has followed in predecessor Jose Mourinho’s footsteps by opting for Diego Lopez over Iker Casillas, but perhaps now is time for the Spain keeper to be reinstated as Real’s number one.