However, Willian insists that playing under Chelsea manager Jose Mourinho was always his first choice.
"Chelsea made an offer two months ago but I was not allowed to leave," Willian told Brazilian television station Sportv.
"I kept following the club and I used to go to London to follow Chelsea whenever I had free time and now my dream has come true. I will work with Mourinho who is the best manager and I will grow a lot with him.
"Other clubs were interested, but my intention and dream of playing for Chelsea made the difference. The opportunity to play with Mourinho, the best manager in the world, also made a lot of difference. I always dreamed of wearing Chelsea's jersey."
Willian is yet to make his Chelsea debut.