Middlesbrough have signed Adama Traore from Aston Villa, with Albert Adomah moving in the opposite direction.
Traore, a 20-year-old winger, joined Villa from Barcelona last year but has now signed a four-year contract with Premier League side Middlesbrough.
Boro boss Aitor Karanka, who previously coached Spain's under-16 side, told his club's official website: "He is another important player and I am expecting a lot from him.
"I've known him since he was a kid. He went into the national team just after I left, but I know all about him and what he can do.