The Brazilian remains an unpopular figure amongst some Spurs fans due to the way he snubbed a move to Tottenham in favour of joining Chelsea in 2013.
Spurs had a deal in place with Anzhi Makhachkala and the winger had checked in for a medical before he was informed about the interest from Chelsea.
Willian claimed that he was in London for two weeks for Spurs to get a deal done to sign him, but admitted that he was not sure about the interest from Chelsea for a long time.
The Brazilian acknowledged that once he heard about the interest from Chelsea, on the day he was supposed to sign for Tottenham, he jumped ship.
The wide-man conceded that it was an awkward decision, but stressed that once Chelsea were in play, he was only going to join one club.
Willian told The Athletic: “I was in London for two weeks, waiting, waiting for Tottenham to decide because they were in a situation where Gareth Bale was in the process of leaving them to join Real Madrid.
“Liverpool were also interested. I wasn’t sure about Chelsea. They’d shown interest but it wasn’t so firm at first.
“Chelsea came on the day I was going to sign the contract with Spurs.
“I was at Tottenham’s training ground to finalise the deal when the call came.
“My agent said to me, ‘Chelsea just called me and they want you’. I said, ‘OK, I want to go there!’.
“Then I left the training ground and went back to the hotel.
“It was a difficult situation because I’d agreed more or less to join Spurs. But in my mind was only Chelsea.
“Once the deal between Anzhi and Chelsea was agreed, I only wanted to go there. It was the best decision of my career.”
Willian went on to win two Premier League titles, a Europa League, an FA Cup and an EFL Cup during his time at Chelsea.
