And the Brazilian was one of few Chelsea stars who didn't appear to down tools for the boss when 2015/16 got off to a awful start.
Anthony Martial of Manchester United applauds the crowd as he is substituted during the Premier League match between Burnley and Manchester United at Turf Moor on January 20, 2018 in Burnley, England.
As things stand, Chelsea are yet to decide whether they would be parting ways with Conte but the choice of sticking with the Italian could witness Willian's exit from the club.
And the bookies have cut the odds on Willian joining United with Mourinho tipped to splash the cash in the coming weeks.
The Red Devils are also in talks with Martial over a new long-term deal, and will trigger a one-year extension option in his current contract anyway before a renewal is agreed on. Reports in recent days have suggested that the 26-year-old is on the lookout for a new club after being told he may not feature regularly under now Arsenal boss Unai Emery.
He said: "Of course (Fred can make an impact), no doubt about that. He has a lot of qualities", Willian said during a press conference before flying to Russian Federation.
Chile are not at the World Cup this year, having missed out during South American qualifying.
"He is very happy to come to the Premier League to play".
"I don't know why he isn't playing more for Manchester United and Jose Mourinho needs to show more confidence in him".
Leeds United have missed out on the signing of Manchester United stopper Dean Henderson after he joined Sheffield United on loan.