Wolves defender Jonny will miss the rest of his side's Europa League campaign and faces a lengthy spell on the sidelines with a knee injury.
The Spaniard damaged his anterior cruciate ligament in Thursday's last-16 win over Greek side Olympiakos.
The 26-year-old wing-back will now have surgery.
Eighteen-year-old defender Lewis Richards will join the first-team squad for Tuesday's quarter-final against Sevilla in Germany.
Wolves doctor Matt Perry told the club's official website: "In the first half of the match with Olympiakos, Jonny suffered an injury to his right knee.
"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."