Isco should be fit to face Atletico Madrid. Getty Images

Spanish national team manager Julen Lopetegui has allayed fears that Isco picked a serious injury on international duty after confirming that the Real Madrid star will be fully fit to play when Los Blancos visit Atletico Madrid on Saturday (18 November).

Isco, 25, was forced off and replaced by club teammate Marco Asensio in the second half of Spain's 5-0 victory over Costa Rica on Saturday following a heavy challenge by Kendall Watson.

The Real Madrid maestro consequently pulled out of the Spain squad ahead of the upcoming friendly against Russia on Tuesday night.

The news set alarms bells ringing at the Santiago Bernabeu ahead of the derby at Atletico Madrid.

However, Lopetegui has played down the fears of Real Madrid fans after assuring that the player will be ready to face Diego Simeone's side.

"It's a knock. It is a knock in the same area that he was hit at Girona. He already had some discomfort then. The feeling is that he was not going to be able to play against Russia but he will not have any problem to be in the next La Liga game [against Atletico Madrid] match," Lopetegui said to Cope. "We decided that the best thing was for him to recover with his team and that's why he withdrew."

Isco was seen limping down the tunnel after Real Madrid's 2-1 defeat at Girona on 29 October.

The Spaniard was then considered doubt for the Champions League trip to Tottenham Hotspur but he eventually managed to recover in time to play against Spurs and Las Palmas before joining up with Spain for the friendly against Costa Rica.

Lopetegui's quotes will be a major relief for Zinedine Zidane after later last week Real Madrid revealed that Gareth Bale is set for a new spell on the sidelines due to a "strain to the middle third of the adductor longus muscle in his left leg".