Willian has been a transfer target for Jose Mourinho since his appointment as Manchester United boss but the Portuguese manager failed in a bid to take him to Old Trafford last summer.
The Brazilian fell out with Chelsea’s boss Antonio Conte last season which saw him block the Italian out of a celebratory Instagram post after Chelsea won the FA Cup against Manchester United.
Barcelona are also reported to have joined the race to sign the 29-year-old from Barcelona as a back-up.
It is claimed that Chelsea would rather sell him to the Spanish Champions than to a direct rival in the league. However, according to the Telegraph, Chelsea would consider selling to United only if the Red Devils will offer Anthony Martial in exchange.
Martial’s agent confirmed last month that the Frenchman wants to leave Old Trafford after he fell out of favour under Mourinho.
The 22-year-old has one more year left on his existing contract but United have an option to extend that by a further year.