Carrick suffered the injury during Saturday’s 2-1 defeat to Liverpool.
“We have some injury problems for tomorrow,” said Ferguson.
“Michael Carrick, as you know, it’s not worked out for us. He came off on Saturday and he’s got a crack in his foot.
“It was diagnosed on Sunday afternoon and he’ll be out for four to six weeks, which is not good news.
“Berbatov is very doubtful following his knee injury in Saturday’s game. There’s one or two other bumps and bruises. Wes Brown got a knee injury, hopefully he’ll be okay tomorrow.
“Berbatov came off and went back on again in the game. There is swelling on the knee but we’re working on that. We’ll see.
“We’ve a good strong squad so we should be okay for what is an important game.”
