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.
Ricardo, now playing his football at Osasuna in La Liga, spoke to the 20-year-old last season and has been impressed with his progress.
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."