Stimson is definitely without key centre-back Simon King and midfielder Stuart Lewis who both have ruptured ankle ligaments, while forward Dennis Oli is also out with a knee problem.
Midfielder Kevin Maher is rated as 50-50 to make his second Gills debut after suffering a dead leg in the friendly defeat to Crystal Palace last weekend.
Alan Julian seems certain to get the nod to start in goal, while the rest of Stimson's team virtually picks itself as he is so short on numbers.
On-loan Josh Gowling will make his debut at the heart of defence alongside Garry Richards in the absence of King, while fellow new signing Chris Palmer is likely to start on the wing.
Stimson must choose between another new-boy - Rashid Yussuff - or youngster Jack Payne to fill in if Maher misses out, while his other new signing Jacob Erskine is likely to be on the bench, where he will be joined by youngsters Tom Wynter and Luke Rooney.
Gillingham 13/10, Swindon 21/10, Draw 9/4