The personal trainer of Wolves attacker Adama Traore admits he holds a grudge over the way he was treated by Barcelona.

Traore is winning praise around the world for his campaign with Wolves this season - including from Liverpool boss Jurgen Klopp and Manchester City's Pepe Guardioa.

Óscar Martínez, founder and CEO of Global Performance, works regularly with Traore and says he was left bitter by the way he was treated by Barca in his final year at La Masia.

He told Sport: "He was hurt, he had rejected offers the previous year and he thought he would do the preseason with the first team, but it wasn't like that."

On Traore's physical development, Martinez added: "We don't talk about strength, but about power. When he arrived at our centre in Barcelona he started with isoinercial training.

"A footballer, to be a professional, must give more than 600 watts of power and Adama stayed at 590. Now, he already exceeds one thousand."