Sean O'Driscoll is sweating over the fitness of Bobby Reid as the Robins search for their first league win of the season.
Reid, who played a key role in the club's 2-1 Johnstone's Paint Trophy win over rivals Bristol Rovers last time out, has an Achilles problem but is the head coach's only injury doubt.
His options are also boosted by the return of defender Derrick Williams after his hamstring injury, while Greg Cunningham and Wes Burns returned from international duty unscathed.
But Jamaica midfielder Marvin Elliott is still returning from his midweek excursions and looks unlikely to feature against free-scoring Posh.
Peterborough captain Tommy Rowe is winning his battle to be fit for the trip south west.
Rowe looks likely to return to the squad after an ankle injury kept him out of the 2-2 draw with Crewe last weekend.
Joe Newell (broken hand) continued his return to fitness by playing 80 minutes in a friendly at Cambridge in midweek and the midfielder is firmly in contention should Posh boss Darren Ferguson choose to alter his starting line-up.
Ferguson made four changes to his team against the Alex but has said he does not envisage anything like that number ahead of the visit to Ashton Gate.