The Brazilian has been in fine form amid a season of turmoil at Stamford Bridge and Mourinho is thought to be keen on a reunion with the former Shakhtar Donetsk man.
And Garth Crooks believes that Willian could be the key to overtaking Pep Guardiola’s side in the Premier League next season, although he is not convinced that Chelsea would sell him.
‘I think this lad has been Chelsea’s best player this season,’ Crooks told the BBC.
‘He provided two assists against Southampton and has been as consistent as anyone in the Blues line-up.
‘Rumours that Manchester United have their sights set on Willian make for interesting reading.
‘Does this mean Paul Pogba or Juan Mata might be surplus to requirements? The bigger question is whether Chelsea would sell another one of their star players to United.
‘If so, Antonio Conte might as well give Mourinho the contact details of the company which engraves the Premier League trophy while he’s at it.’