Reading boss Brian McDermott is waiting on a host of first-team players ahead of the game.
Full-back Andy Griffin has missed the last six games with an Achilles injury but is back in training and could be ready for a return.
Winger Jobi McAnuff is also close to a comeback following a hamstring injury while Australian goalkeeper Adam Federici is back in contention after a knee problem but is not yet fit to start.
Striker Noel Hunt (foot) is a doubt along with on-loan QPR midfielder Mikele Leigertwood (calf) and defender Matt Mills (groin).
McDermott trimmed his squad on deadline-day last week as left-back Marcus Williams joined Scunthorpe on loan and defender Sean Morrison moved to Huddersfield.
David Nugent will be fit for Portsmouth.
The former England international hobbled out of Pompey's 1-0 win over Leicester with a dead leg but the international break gave him plenty of time to recover.
Fellow forward Danny Webber is the only absentee as he steps up his rehabilitation from a cruciate injury.
Defender Aaron Mokoena, who was dropped by South Africa for their Africa Cup of Nations qualifier against Egypt last week, could return to the bench.
Rookie midfielder Tom Kilbey, who was among the substitutes at the Walkers Stadium, has since joined Lincoln on loan.
Goalkeeper Jamie Ashdown, defender Greg Halford and striker Dave Kitson will line up against their former club.