Asenjo was substituted with six minutes remaining in his side’s 1-0 defeat after falling awkwardly having jumped for a high ball in his penalty area, and scans confirmed the club’s worst fears.
A statement on the club’s website read: “After examinations and tests this morning after last night’s game against Atletico Madrid, Villarreal medical services report that Sergio Asenjo has suffered a rupture of the anterior cruciate ligament in his right knee, combined with some lesser injuries, and will require surgery.
“The club will issue further information in the coming hours. Villarreal CF want to provide their full support and encouragement to the player and wish him a speedy and successful recovery.”
The injury could keep Asenjo out of action for around six months, which would see him miss not just the remainder of the season but the start of the 2015-16 campaign.
Former Liverpool and Chelsea striker Fernando Torres scored Atletico’s winner in Wednesday evening’s match.