Madrid, Nov 16 (IANS): FC Barcelona suffered a setback when it was confirmed that central defender Javier Mascherano will be out of action for a month after suffering a hamstring injury in a friendly game between Argentina and Nigeria.

The injury comes at a bad time for Barcelona ahead of a tough run of matches between now and Christmas which will end when Barcelona visit the Santiago Bernabeu Stadium to play Real Madrid on December 23, reports Xinhua news agency.

The possible problems for Barca boss Ernesto Valverde are also increased by the fact that his first choice pair of central defenders, Gerard Pique and Samuel Umtiti, are both just one booking each away from suspension.

The only other specialist central defender in the squad, Thomas Vermaelen, has been limited to just one King's Cup appearance this campaign although he has continued to play for Belgium at international level.

Mascherano will miss the Liga Santander matches against Leganes, Valencia, Celta Vigo, Villarreal and Deportivo la Coruna and it will be touch and go whether he is fit for the 'Classico'.