Chairman Darragh MacAnthony, the man responsible with Ferguson for guiding Posh back into the second tier of English football, remains fully behind his manager and wants the town of Peterborough to do the same.
Labelling the midweek attendance at London Road as 'pathetic', United fans have been urged to make Forest's visit a sell-out.
He told the Peterborough Evening Telegraph: "(Let's) make it a horrible place for Forest to play at and let's get our season back on track quickly."