"There was a lot of speculation regarding Real Madrid," Diego told Radio Brasil. "Many things had been said but I never had any contact with anyone linked to that team.
"I am focused on Werder Bremen and I have just renewed my contract here."
However, Diego did confirm there was a clause in his new contract which would allow him to move to a big club at the end of the season.
"I heard that in Spain it is being said that I have a rule in my contract that authorises me to leave to a European giant when the season ends. It's true, but for the moment this isn't something that I have in mind," he added.