The father and agent of Diego has urged Juventus to step up negotiations for the Werder Bremen midfielder.

"Did you see what he did at the Stadio Friuli when he was only 30 per cent fit? I will let you imagine what he can do when he's at his best," he told Tuttosport.

"I have already confirmed that with Juventus he aims to become one of the best players in the world. He wants to win many important trophies.

"Next week there should be a meeting between [Juve director of sport Alessio] Secco and [his Werder Bremen counterpart] Allofs.

"We have already made our choice, now it's up to the clubs to reach an agreement."