Sociedad's Vela to undergo knee surgery

San Sebastian, Spain ( - Real Sociedad will be without leading scorer Carlos Vela for a spell after the Mexico international suffered a torn meniscus in his team's 4-1 defeat to Real Madrid over the weekend.

Vela had to be substituted after 17 minutes when he twisted his knee, and tests have confirmed the extent of the problem, which is expected to keep the forward out at least six weeks.

The loss of Vela is a blow to manager David Moyes, with Vela having been in good form prior to the injury.

Vela, 25, has scored seven goals in La Liga this term, but Sociedad will now have to rely on the forward duo of Imanol Agirretxe and Alfred Finnbogason, who have combined to score just two goals in 30 appearances.