Ricardo, now with Osasuna, had three years at United.
"You have to be cautious with transfers, until they happen it's often better to say nothing and not talk about it. All I can say is that de Gea is a very reliable keeper and his career rise has been meteoric and he has dealt with everything very well," he told AS.
He added: "Last season he came to Osasuna with Atletico and I had the chance to talk to him. At the time he was a substitute behind Asenjo. Now he is the keeper of a great team like Atletico Madrid and he should also focus on enjoying it."