The Spanish wing-back was forced off in the first half of Wolves' 1-0 victory over Olympiacos on Friday (AEST) and he is now set for an extended period on the sidelines.

Academy defender Lewis Richards will join up with the first team in Germany ahead of Wednesday's (AEST) quarter-final against Sevilla.

Wolves doctor Matt Perry said: "In the first-half of the match with Olympiacos Jonny suffered an injury to his right knee.

"Yesterday [Saturday AEST] a scan confirmed the first clinical impression of an injury to the anterior cruciate ligament which will require surgical repair.

"This has been arranged and the whole team wish Jonny well on his path to recovery."