Dickinson had to be replaced at half-time in the 2-1 defeat to Doncaster on Tuesday night after complaining of a hamstring injury and he remains a concern.
Reuben Reid replaced Dickinson in midweek and could start if required as Posh look to build on their first away win of the season at Watford last weekend.
Midfielders Lee Frecklington (calf) and Chris Whelpdale (groin) are also set to be missing while defender Kerrea Gilbert is hoping to return from a knock.
Record signing Ryan Bennett remains sidelined as he recovers from an ankle injury while Posh fans will not get the chance to see former captain George Boyd.
Boyd joined Forest on loan at the start of March but is not allowed to feature against his former employers.