Chelsea's Willian has backed Brazil team-mate Fred to be a major success at Manchester United and said he is moving to "one of the best teams in the world."
Midfielder Fred is set to join Jose Mourinho's side for next season after a transfer in excess of £50million was agreed with Shakhtar Donetsk on Tuesday.
Chelsea forward Willian, who is currently on international duty with the 25-year-old ahead of the World Cup, believes he has a bright future and will make the grade in England.
"Of course, no doubt, no doubt about that," replied Willian when asked if Fred will thrive in the Premier League.
"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."
In addition to their national team connections, the pair were both introduced to European football in Ukraine.
Willian spent five-and-a-half years with Shakhtar before leaving in January 2013 for a short spell with Russian club Anzhi Makhachkala, while Fred arrived in Donetsk from Brazilian side Internacional five months later.
Willian said he has given advice to Fred about playing in England but insists both men are fully focused on the World Cup ahead of their country's final warm-up friendly against Austria on Sunday.
"He's very happy to come to the Premier League to play, we talked a little bit about that," added Willian, who switched to Chelsea in the summer of 2013.
"He's excited to start but now it's time to think about the World Cup and think about the national team."
Willian's own future in club football appears to be in doubt amid speculation he wants to leave Stamford Bridge.
He was voted players' player of the year by his Blues team-mates and picked up the goal of the season award but was often used as a substitute by manager Antonio Conte.
The 29-year-old, who has scored eight times in 55 international appearances, felt last season was a good one personally but was coy about his plans after the summer.
"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. I'm ready for it."
