Rovers lose 2-0 on the road after a battling performance against The Posh.
Joey Barton selected an unchanged starting XI from the side that beat Wigan 4-1 at the Mem.
The first chance of the game fell to John Marquis, who turned his defender but his attempted lob effort flew over the bar.
A chance came for the hosts when Jack Hunt sprinted back to make a brilliant recovery tackle to deny The Posh a shot on goal.
Peterborough took the lead as Archie Collins' deflected volley found its way into the bottom left corner of the Rovers net and subsequently, Rovers went into the break a goal down.
The Posh scored just minutes after the break when Cox made a fantastic diving save but the ball went straight into the feet of Ajiboye who scored.
An early change came for Rovers when Luke Thomas picked up an injury and Jevani Brown came on.
Rovers almost replied instantly as Collins had a chance from metres out, but the shot was blocked on the line.
A yellow card was given to Evans after a late sliding challenge on Ajiboye.
Sam Finley gave Rovers an opportunity when his brilliant tackle high up the pitch who passed the ball to Marquis, goalwards and took a shot which was deflected behind for a corner.
Jevani Brown got the ball inside the box and curled a shot onto the near post. Easily one of the better chances of the game.
Rovers made more changes as Ryan Woods and debutant Chris Martin came on for Evans and Finley.
Barton made some more late substitutions when Marquis and Bogarde made way for McCormick and Sinclair.
Aaron Collins couldn't give the travelling fans a consolation after Chris Martin headed a long ball down and the winger's shot just rolled wide of the post.