Villas-Boas signed the Spain international when he was in charge at Stamford Bridge.
"It's not my decision to pick or not pick Mata, it was before," he said.
"He was always involved in my starting XI, I have always enjoyed a great personal and professional relationship with Juan Mata but it's not my decision anymore."
"I suppose the time that he's not being given now, with the talent that he has he will overcome it and jump back into the team because he is that player, that special."
But when asked if he was interested in signing Mata, Vilas-Boas simply said: "No, I don't think so."