The Bulgarian striker found himself behind Wayne Rooney and Javier Hernandez in the pecking order towards the end of last season.
Ferguson also overlooked the 30-year-old when selecting his 18-man squad for May's Champions League final against Barcelona, preferring Michael Owen in the substitute's role.
Speculation has been rife all summer that Berbatov would leave Old Trafford, and the United manager acknowledged that his £30.75 million signing may be unsettled.
"Yes, I'd understand [if Berbatov requested a transfer]," Ferguson told press during United's tour of America.
"But you could say that about all my forwards. I don't pick the same team every week do I? I've only done that once in the last three years.
"But he has been brilliant, first class. His training has been terrific and he's a good type of person. A good guy."
Berbatov ended last season as the Premier League's joint top goalscorer with 21 goals, sharing the award with Manchester City's Carlos Tevez.