Chelsea midfielder and La Masia graduate Oriol Romeu will be out for approximately six months after undergoing an operation on Monday to reconstruct his anterior cruciate ligament (ACL).

The Spaniard had reconstructive surgery on his ACL, as well as a medial meniscus repair, after a rupture during the first half of a 3-1 win at the Stadium of Light against Sunderland. Against the Black Cats he lasted only 20 minutes before being stretchered off the field to make way for Oscar.

To date, Romeu has appeared 33 times for Chelsea since arriving from Barcelona’s Camp Nou in the summer of 2011. So far this season the defensive midfielder has made nine appearances for the Blues in all competitions, with a goal coming in their Capital One Cup win against Wolves three months ago.

The procedure on Romeu’s ACL and medial meniscus will sideline the player for six months, which comes as a blow for the team before their flight to Japan for the FIFA Club World Cup. It had initially been though that Romeu would join up with the squad later this week, however further study showed the requirement for surgery.

The Spaniard will now stay home in London for observation. Meanwhile, his team-mates make their way to the tournament, looking to help manager Rafael Benitez lift the trophy for a second time after his success at Inter Milan in 2010.