Real Madrid will be without Gareth Bale for their Champions League Group B game against Copenhagen on Wednesday.
The 24-year-old winger aggravated a thigh injury during Los Blancos' 1-0 defeat to local rivals Atletico Madrid in La Liga on Saturday.
"The player Gareth Bale did not train with the group on account of a muscle strain in his left thigh," read a statement on the club's official website. "The diagnosis is pending a series of tests to be conducted tomorrow (Wednesday)."
Bale joined Madrid from Tottenham Hotspur in the summer for a reported transfer fee of £85m.