Swindon boss Paolo Di Canio has several injury concerns ahead of the visit of Orient.
The Robins will definitely be without Gary Roberts and Giles Coke through injury, while defender Troy Archibald-Henville is rated doubtful at best.
Matt Ritchie is also a doubt with a hamstring injury, but striker James Collins is expected to return after missing the Robins' midweek loss to local rivals Oxford United in the Johnstone's Paint Trophy.
Di Canio must decide whether to return Collins alongside summer signing Andy Williams up front or drop the former Yeovil man to the bench.
Williams, fifth top scorer in League One last season with 16 goals, is yet to open his Town account since moving from the Glovers.
Leyton Orient will check on Jamie Jones and Lloyd James.
First-choice goalkeeper Jones sat out last weekend's 1-0 defeat by Crawley to rest the shoulder injury which sidelined him last season, with Ryan Allsop drafted in.
Full-back James has been struggling with an ankle injury and was replaced by Leon McSweeney, who made his first start of the season.
Fellow defender Scott Cuthbert is still on the sidelines due to a hamstring injury.
Former QPR duo Martin Rowlands and Lee Cook should keep their places in midfield after making their full debuts last week.
Ryan Brunt and Marc Laird were on target for the reserves in midweek to push their claims for recalls.