Espanyol's Osvaldo out for two months
The Argentine forward, Espanyol's top scorer with seven goals, was stretchered off after suffering the injury during the first half of Sunday's 4-0 La Liga win at home to Real Zaragoza.
He has almost completely ruptured an adductor muscle in his left thigh and doctors have recommended surgery, though a final decision will be taken in the coming hours, the club said on their website.
The injury is a major blow to Mauricio Pochettino's side, who are pushing for a Champions League qualification place for next season. They lie fifth in the standings three points behind fourth-placed Valencia.