Carvajal's contract at Bayer carries a buy-back option for Real.
"I have faith in myself and I feel ready to go back to Real or to play in the Champions League with Leverkusen. I think of myself as a Madrid supporter. I was born a Madrid fan.
"I wore the shirt for 10 years and Madrid is in my blood. At the moment, I'm with Bayer until 2017 and I don't know if I'll go back."