So far this season Berbatov has featured in just one game when he came on as a sub in the match with West Brom.
Last night Anders Lindegaard, Antonio Valencia and Darren Fletcher all made their first appearances of the season and it looked like the ideal game to let Berbatov loose, but the boss went with Rooney as a lone striker and introduced Hernandez later in the game.
"It is hard because of the number of strikers we have," Ferguson said.
"Michael Owen is there, Federico Macheda, Mame Biram Diouf. Danny Welbeck won't be back next week but probably the week after. It is not easy.
"Dimitar has been training terrific. His attitude is spot on. He will get his game time as the season wears on. There is no question about that."