Former Atletico Madrid midfielder Diego has no doubts about the potential of Real Madrid signing Vinicius Junior.
Diego plays with the teen at Flamengo.
He told AS: "I rate his evolution since he came up to the first team as excellent.
"From the beginning, we all saw that he was a player with a differentiated talent and it was only a matter of time until he began to help the team at key moments, as he is doing.
"There's no reason for concern at Madrid about his development here.
"Vinícius is a very disciplined player, has an exemplary conduct and is surprisingly mature for his young age. He is a footballer who cares to dedicate himself to the maximum in his training, who always wants to evolve. And there's plenty of quality about him."