The Premier League club confirmed on Tuesday that they have reached an agreement with Shakhtar Donetsk for midfielder in a deal believed to be worth around €55 million, which could rise to €60m with add-ons.

Chelsea star Willian, who has also been linked with a move to Old Trafford, has "no doubt" that Fred will make the grade in England's top flight.

"Of course, no doubt, no doubt about that," Willian said. "He has a lot of quality, he can improve a lot. He goes to one of the best teams in the world and I'm happy for him.

"I hope he does well at Manchester United. He's very happy to come to the Premier League to play, we talked a little bit about that. He's excited to start but now it's time to think about the World Cup and think about the national team."

Brazil legend Rivaldo echoed Willian's sentiments, but urged Manchester United to give the 25-year-old time to settle in his new surrounds.

"He is a wonderful player," the former world footballer of the year said.

"Like any other player when you move to a new country, he will need a little bit of time to adapt.

"But when you are a good player and a brilliant midfielder like he is, he is going to do well and he is going to be good for Manchester United and they will be good for him."

Willian, who made almost as many Premier League appearances (16) off the substitutes bench as he did starts (20) last season, remained coy when pushed on plans his own future.

"I was happy with my performance during the season, I played very well, I always try to do my best, always try to work hard and sometimes to stay on the bench is difficult but I respect the decision of the manager, always," he said.

"I don't have any more to say about my club because now I want to have focus here with the national team on the World Cup."

The Brazil squad, currently preparing for Sunday's friendly against Austria at Tottenham's Enfield Centre, were quick to congratulate Fred on Tuesday after his move was confirmed.

Winger Douglas Costa trained with the rest of the team for the first time since World Cup preparations began two weeks ago.

Costa picked up a thigh injury during Juventus' 2-1 win against Verona in the last round of the Italian Serie A season.

Midfielder Renato Augusto, however, did not train on Tuesday. He is still recovering from a knee injury.

Brazil's team doctor Rodrigo Lasmar said this week that it's doubtful whether Costa and Augusto will play Sunday's friendly. Both missed Brazil's 2-0 win over Croatia in Liverpool this past weekend.

Brazil start their World Cup campaign against Switzerland in Rostov on June 17.