Sociedad's Mexico forward Vela to undergo knee surgery

(Reuters) - Real Sociedad's Mexico forward Carlos Vela faces a long spell on the sidelines with a knee injury that requires surgery, the La Liga club said on their website on Monday.

Sociedad's top scorer went off injured after 17 minutes in the 4-1 defeat at Real Madrid on Saturday and will have an operation to repair a torn meniscus in his right knee.

"During the game that took place in Madrid, Vela sustained an injury to his right knee. Tests have revealed a tear in his internal meniscus," the club said on www.realsociedad.com.

"Having reviewed the situation, we have opted for the player to have an operation. Carlos will undergo surgery today (Monday) carried out by doctor Mikel Sanchez."

The 25-year-old former Arsenal player has scored seven goals in 20 league games this season for Sociedad who are 13th in the La Liga table and stand four points above the relegation zone.

(Writing by Ken Ferris; Editing Ed Osmond)