The Inter boss has been linked with a summer return to the Premier League side.
“My honest answer is that I don’t think it is likely to happen,” Buck said.
“Jose was a great coach, he is a great guy, but I think his time at Chelsea Football Club has passed.”
He added: “We didn’t fire him. It was mutual that he left the club.
“The board and Jose were not seeing eye to eye on a number of things and it was time we parted company.”
