It’d be the second player the Portuguese boss has signed from his form club after previously completing a deal for Nemanja Matic in a £40million move earlier in the window.
The Portuguese boss would be reunited with another key figure from his 2014-15 title winning side at Stamford Bridge and would be ready to take on the new season.
He has already massively strengthened the spine of his side and has signed the likes Romelu Lukaku from Everton, Victor Lindelof from Benfica and Matic from Chelsea.
The side have still been on the lookout for a new wide man as he usually employs a 3-4-3 and a 4-2-3-1, and with a deal for Ivan Perisic breaking down, he has turned his sights to Willian.
He has already confirmed he would like to sign a new player before the end of the window, but has claimed he won’t be putting any pressure on the board as they’ve already done so well in delivering most of his targets.
Willian is likely to cost around £35million having joined Chelsea for £30million from Russian side Anzi Makhachkala back in August 2013 and a move could be on the cards as Mourinho attempts to recruit his services.