The 24-year-old Brazilian was the subject of a bid from the Blues back in January while André Villas-Boas was still in charge at Stamford Bridge.
Spurs have also been linked with a January swoop for the midfielder since the Portuguese coach took over at White Hart Lane in the summer.
Willian is keen to secure a move away from Shakhtar Donetsk to test himself in one of Europe’s top leagues – but admits he does not know if Spurs or Chelsea will bid for him again.
“Chelsea and Tottenham Hotspur have made offers for me in the past. Who knows what will happen in the future? Maybe they will come back,” Willian said.
“At the moment all I am thinking about is Shakhtar and helping them to qualify for the next round of the Champions League.
“But I have always thought that one day I want to play for a big club in England, Spain or Italy, so it’s very important for me to play so well against such an important team as Chelsea.”
Chelsea boss Roberto Di Matteo last month revealed that he is a keen admirer of the attacking midfielder after confirming the Blues’ interest in him earlier in the year.
“As an assistant [to Villas-Boas at the time] I wasn’t involved in those conversations but Willian is a fantastic player with good qualities,” said Di Matteo.
“We have a good squad with good players and I don’t know where his future is, but the way he is playing here he looks quite happy.”
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news