Real Madrid star Isco is a doubt for El Derbi against Atletico Madrid after the club confirmed he was facing surgery due to acute appendicitis.

Isco experienced stomach pains on Tuesday, one day before Madrid travel to the Ramon Sanchez Pizjuan to face Sevilla in LaLiga.

Madrid coach Julen Lopetegui did not give a timetable for the Spain international's return, but it appears unlikely he will be fit for the derby at home against Atletico on Saturday.

"He had a stomach pain this morning. It looks like appendicitis," Lopetegui told a news conference.

"Hopefully it's a speedy recovery. When a player's out it's always bad news and we wish him a speedy recovery.

"We've got a good squad and somebody else will have to play. I have total confidence in the rest of my players."

"I have not been able to talk to him. He's about to go into surgery. I hope he can quickly get back into shape."

Dani Carvajal did not train with his Madrid team-mates on Tuesday and could also be set to miss the clash with Diego Simeone's side.

"We'll see [if Carvajal will miss El Derbi]. He had an overload and has not improved as we expected," said Lopetegui, who confirmed he will sit out the match in Andalusia.

"We have to wait. He will not play against Sevilla. It's an injury you have to look at day by day.

"Injuries will happen. In this case it's been unfortunate, but they are normal. We have to face them with a level head and with confidence in the player who comes in."