Right-back Solly missed Saturday's 1-0 home defeat by Burnley due to a dead leg and midfielder Stephens also sat out with a knock.
Striker Yann Kermorgant will miss out again as he serves the second match of a three-game ban for his red card against Nottingham Forest last weekend.
Manager Chris Powell dropped goalkeeper Ben Hamer against the Clarets following some below-par displays and gave David Button his league debut, so he could keep his place.
Danny Hollands is still out with a fractured metatarsal but fellow midfielder Andy Hughes made the bench on Saturday following a long-term Achilles problem and will be hoping to feature again.
Peterborough boss Darren Ferguson will welcome back Kgosi Ntlhe. The teenage left-back finally returns to the squad after recovering from a broken ankle but may have to settle for a place on the bench.
Striker Tyrone Barnett was named amongst the substitutes for Saturday's win at Blackburn on his return from a knee injury and is pushing for inclusion.
Barnett is unlikely to displace hat-trick hero Dwight Gayle, though, who collected the match ball in their victory at Ewood Park.
Loan trio Alex Pritchard, Scott Wootton and Davide Petrucci all remain sidelined.
Posh have won three of their last five league matches and are now just a point from safety in the npower Championship.