He struck up a good relationship with Mourinho during their time together at Stamford Bridge, and it seems Willian could be open to a move across London if Chelsea let him go.
Speaking fondly of his old manager, Willian said on Thursday: "People ask me about the best coaches I have had. For sure, Mourinho is one of them.
“We had a special relationship. He demanded a lot, so there were some conflicts, but that's normal.
"He would challenge me and call out my mistakes, but if I had played well he would also say something like, 'today you killed it'.
“I loved his man-management, how he organised training, how he spoke in meetings. I learned a lot from him."
It was Mourinho who brought Willian to the club, and they have remained in contact since the Portuguese coach departed in 2015.
“Even after he left Chelsea he spoke well of me," Willian added. "We are still friends. Sometimes we exchange messages.
“When he was at Manchester United he wanted me to go there. And the way in which he made that clear was always respectful."