Reading are sweating over the fitness of Joseph Mills once again.
Full-back Mills has an ankle injury which kept him out of the Royals' dramatic 3-2 victory at Ipswich on Saturday and he remains a doubt to face Posh.
Veteran defender Ian Harte filled in for Mills at Portman Road, and the Irishman is likely to keep his place in manager Brian McDermott's side as Reading look to bounce back to winning ways at home after losing 2-1 to Cardiff at the Madejski Stadium 10 days ago.
Meanwhile, Brynjar Gunnarsson remains sidelined with the calf strain he picked up in a reserve-team fixture, but centre-back Bongani Khumalo has returned to training following the ankle problem.
Young striker Nicholas Bignall is also out of contention as he recovers from the knee surgery which cut short his loan spell at Wycombe.
Peterborough boss Darren Ferguson will choose from an unchanged squad.
Ferguson must decide whether to stick with the same starting XI or make changes at the Madejski Stadium.
Ferguson was forced to make one change to his team for the visit of Middlesbrough on Saturday, with Tom Kennedy replacing the injured Mark Little (groin) at right-back.
Midfielder Ryan Tunnicliffe and striker Emile Sinclair might have put themselves in the frame for recalls after their introduction from the bench coincided with Posh's equalising goal in the draw against Boro.
Defender Josh Thompson, midfielder Daniel Kearns and striker David Ball are also options for Ferguson should he feel the need to make changes.