Midfielder O'Connor (ankle) and striker El Alagui (knee) have been sidelined since early in the season, but have now been back in training for a couple of weeks and got two reserve outings under their belts.
Manager Uwe Rosler this week admitted the duo are pushing for places on the bench.
Defender Scott Barron remains sidelined after a hip operation and back-up goalkeeper Richard Lee has had shoulder surgery, with neither expected back before the end of the season.
Rosler will rotate his squad following Monday's 2-0 defeat at MK Dons, with Bradley Wright-Phillips set to replace Marcello Trotta in attack after the latter was hauled off at half-time.
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