Bradley, the centre-half signed from Plymouth Argyle in the summer, impressed enough on his first competitive start for the club in the midweek Carabao Cup defeat at West Brom to earn a place in the starting line-up at the Abax Stadium.
Missing out from the 1-1 draw with the Black Cats is midfielder Jorge Grant, the on-loan Nottingham Forest man dropping to the bench.
On the bench for Posh – third in the table after back-to-back wins in their opening two fixtures – is former Hatters goalkeeper Mark Tyler, who doubles up as goalkeeper coach.
TOWN: Stech, Stacey, Pearson, Sheehan ©, Bradley, Potts, McCormack, Mpanzu, Lee, Hylton, Collins. Subs: Justin, Shinnie, Cornick, Jervis, Rea, Grant, Shea (GK)
POSH: Chapman, Naismith, Daniel, Woodyard ©, Tafazolli, O’Hara, Godden, Dembele, Ward, Bennett, Cummings. Subs: Tyler (GK), Reed, Cooke, Toney, Cooper, Yorwerth, Maddison.
REFEREE: Graham Salisbury