Chelsea boss Guus Hiddink says the club must keep hold of Willian.
Guangzhou Evergrande are willing to spend £50m on the Brazil playmaker – one of the outgoing Premier league champions' few success stories this season.
But Hiddink says: “I have known Willian for many years, before the Chelsea time. As a person, he is very nice and down to earth. On top of that, he is doing a very good job.
“This year, a difficult year, he is working hard with his natural ability and sacrificing himself. When they defend and sacrifice themselves, he has the attitude to do so. He can be a key player at this club."