Swindon defender Rob Hunt is not fit enough for the visit of Portsmouth.
The right-back is training but has not played since the start of March because of injury and is not ready to return.
Defender Paul Cassis has a minor hamstring problem which could make him doubtful.
Ellis Iandolo, Zeki Fryers, Mathieu Baudry (all hamstring) and Dion Conroy (Achilles) remain absent while Akin Odimayo will see a specialist about his knee problem at the end of this week.
Portsmouth defender Jack Whatmough starts a suspension after his sending-off against MK Dons at the weekend.
Midfielder Ben Close could return after a groin issue kept him out on Saturday, while defender Lee Brown is close to recovering from the hamstring problem which has seen him miss the last two games.
Andy Cannon continues to struggle with a back problem which restricted him to a short substitute role at the weekend.
Ellis Harrison and Michael Jacobs (both knee) are absent for the remainder of the season, while Jordy Hiwula is still missing with an ankle injury.