The former Chelsea manager achieved a historic Treble with Inter last season.
When asked if he would ever go back, Mourinho replied: "Why not? We were always happy together."
"I prefer it that Ibrahimovic is at Milan rather than at Barcelona.
"In the end we'll only meet him twice in the Champions League, while at Barcelona we would have had to face him for an entire season.
"He is a great player," Mourinho concluded.