FC Barcelona face an injury crisis in defense after it was confirmed that Spain international left back Jordi Alba will be out of action for three weeks after tearing his hamstring on Saturday night.

Alba lasted less than a quarter of an hour of Barca s frantic 3-2 home win against Sevilla before limping off to be replaced by Adriano.

First indications were that he would be sidelined for between two and three weeks, but tests carried out on Sunday morning confirmed the duration of the injury would be three weeks. That means he will miss four league matches and his side's debut in the Champions League at home to Ajax this week.

With central defender Carles Puyol still on his way back to fitness following a long-term knee injury, Alba's absence is a real problem for coach Tato Martino, given that Adriano appears to currently be the first choice to cover for habitual central defensive pairing of Gerard Pique and Javier Mascherano. Should either of those two get injured or suspended before Puyol is fit, youngster Marc Bartra, who clearly doesn't enjoy Martino's confidence would be called into action and with a busy schedule lying ahead Martino must be worried, although he preferred to discuss other matters in his post game press conference, such as his side's problems in defending set pieces.

"I am not going to change our policy of man to man marking," he said. "We are going to carry on defending in that style because it is the best way of doing so as it is tough to do zonal marking because we are not a big side," he said when asked over the corner which saw Sevilla take a late equalizer before Alexis Sanchez sealed the points with a late winner.

Martino refused to rule out whether the club would sign a defender in the winter transfer market, but nor would he confirm that a new player was certain to arrive.

"We will study the winter market, but we are not certain to sign anyone, especially if Puyol responds well," he said.

The Barca coach also had words of praise for Leo Messi, as well as Neymar, who enjoyed his best 45 minutes as a Barca player, while adding that Andres Iniesta was looking fitter all of the time.

"We are obliged to have him in good shape as well aas Xavi Hernandez and Cesc and we will do all we can all we can to ensure that is the case," he concluded.