The former Real Madrid defender has made only one first team appearance in Spanish football.
"I'm very happy at Chelsea but I would like to return to play in Spain one day," he told Cadena Ser.
"Obviously, before I retire I would like to play in La Liga because I haven't played much there.
"But I'm very happy in London. All I think about is Saturday's game against Crystal Palace.
“I really like the Premier League and to have the opportunity to play for Chelsea and win titles."