Willian is convinced his Brazil team-mate Fred will be a success at Manchester United and also said he has moved to "one of the best teams in the world."
Fred is on the verge of joining the Red Devils after a transfer in excess of £50million was agreed with Shakhtar Donetsk on Tuesday.
However, Willian, who switched to Chelsea in the summer of 2013, reckons his compatriot will shine in England.
"Of course, no doubt, no doubt about that," replied Willian when asked if Fred will thrive in the Premier League, Mirror reported.
"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 added: "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."