The Brazil international is contracted to the Blues until the end of the 2019-20 season but his long-term future at Stamford Bridge remains open for discussion.
According to Football Insider, Mourinho has already held talks with Willian over a potential move to the Tottenham Hotspur Stadium, and Spurs have now put a lucrative contract on the table.
The report claims that Willian has also been offered 'a big signing-on fee' to move to North London.
The South American, who is believed to want a three-year deal at Chelsea, has scored 11 times and provided nine assists in 43 appearances for Frank Lampard's side this season.
The 31-year-old has been in impressive form for the Blues since the Premier League restart last month, scoring four times and providing two assists in five top-flight appearances. body check tags ::