Berbatov joined United from Tottenham on transfer deadline day for around £30million.
“It is enjoyable (working under Ferguson). Sometimes you get a little bit nervous around him because obviously he is Sir Alex. You don’t know what to say or do sometimes,” Berbatov told Sky Sports
“He is a really nice guy. He speaks with you when necessary, or sometimes he raises his voice to make his point clear.”
He continued: “It is up to Sir Alex who plays. Everybody wants to play and I think in some games we could even play all four strikers.
“But of course there will be rotation and it is difficult when you don’t play some games. That is football.
“I am still working on everything. Everything is new to me. I am still working on my training sessions and my performance in games.
“But I think, for now, things are going according to plan. I am working hard and fighting for my place.
“Sir Alex is in charge and you must prove to him in every training session and every game. And I am trying to do that.”
