The Bulgarian arrived at Old Trafford from Tottenham Hotspur in 2008 after a lengthy pursuit that went to the final hours of the transfer window.
United's record signing has cut a forlorn figure since being left out of the 2011 Champions League final defeat to Barcelona.
The 31-year-old has fallen down the pecking order behind Danny Welbeck, Wayne Rooney and Javier Hernandez and made just 12 Premier League appearances last season.
Berbatov has been linked with a move to AC Milan as a replacement for new Paris Saint-Germain signing Zlatan Ibrahimovic.
Ferguson selected the former Spurs front-man in a midfield role during Wednesday's pre-season 1-0 win over AmaZulu and confessed his mixed feelings over the striker.
"I do not need to herald the abilities of Dimitar Berbatov, he is a fantastic talent," said Ferguson.
"Last season he didn't quite get the amount of football he wants. At his age, it was difficult for him to accept his position in the forward line.
"He had Rooney, Welbeck and Hernandez in front of him, and they are all young men.
"The boy has a future, but if he wants to leave it is a different matter.
"I am easy about it if he stays. I would be happy with that. But if someone comes in and Dimitar wants to leave, we will assess it."
