David Luiz believes Chelsea teenager Ethan Ampadu has already proven he's a man.

The 17-year-old, who has two caps for Wales, has partnered Luiz at centre-back in both of Chelsea's preseason matches.

And the Brazilian says he's tried to help him improve this summer, but insists Ampadu is already a mature player.

"He's a fantastic boy, a fantastic player. He's humble, he has his feet on the ground, he tries to learn every day," Luiz said. "He's 17, almost 18 but for me he is already a man playing football, he's great for me to have this opportunity with this youngster who is already a man.

"I have played with many players, different age, different times of life, so it is great to a player like him here. I try to advise him with many things, I have seen a lot of things in my career have lived a lot of things in my career, so I try to help him in the best way because he deserves the best advice."