Midfielder Bridcutt picked up his fifth yellow card of the season in Friday night's 2-2 draw with Leeds and serves a one-match ban, while centre-half El-Abd is struggling with a hamstring injury.
Andrew Crofts or Gary Dicker will replace Bridcutt in the centre while Lewis Dunk is on standby to make his first npower Championship appearance of the season should El-Abd miss out.
Andrea Orlandi should retain his place in midfield after impressing on his return from injury against the Whites, but fellow Spaniard Vicente is still missing with a thigh problem.
Stephen Dobbie, Kazenga LuaLua and David Lopez are further attacking options for boss Gus Poyet as his side attempt to end a seven-match winless streak.
Peterborough will be without Kgosi Ntlhe.
Full-back Ntlhe was forced off with an injury after 62 minutes of the 2-1 defeat to Sheffield Wednesday at Hillsborough on Saturday. Posh are awaiting the results of a scan to determine the extent of the problem.
Tommy Rowe had a second scan on his troublesome ankle injury last week and remained absent against the Owls. The wing-back has missed the last three matches and is rated at 50-50 to return to the squad for Tuesday night's game.
Peter Grant and Dave Hibbert are Peterborough's other absentees.
Grant was to undergo a knee operation and is expected to spend an extended spell on the sidelines. Hibbert, meanwhile, is closing in on a first-team return after almost two years out with a serious knee injury.
