Luka Modric has "an injury to the back of his left thigh" Real Madrid said on Friday, casting doubt on whether he will be fit to face Manchester City in their Champions League semi-final first leg match.

The Real statement gave no further details but Spanish media reported the 37-year-old Croatian star will be out for about ten days.

The Spanish cup final is on May 6 and the first leg of the Champions League semi-final against the English champions is in Madrid on May 9.

Modric was replaced by French international midfielder Aurelien Tchouameni in the 63rd minute as Real lost 4-2 to Girona in La Liga on Tuesday.

"He had a minor injury in Girona and is unavailable," coach Carlo Ancelotti told a press conference on Friday.

"We're waiting to see how he progresses and I don't know if he will make the cup final.

"Let's hope we have him back for the remaining games, which are important."

In La Liga, Real face Almeria on Saturday and visit Real Sociedad on Tuesday before playing Osasuna in the Spanish cup final in Seville.