Right-back Hunt (hamstring) and centre-half Gerrard (calf) missed the draw with Peterborough after sustaining injury during last week's defeat at Bolton, while winger Danny Ward remains doubtful for the weekend due to a groin strain.
"We lost Danny Ward (on Friday) and we knew Anthony Gerrard would be touch and go with an injury he picked up in Tuesday night's game," Robins said after Saturday's 2-2 draw.
"We also knew Jack Hunt had no chance of playing in this game, but that is football and you have to respond. That's what a squad is for.
"Hopefully Anthony will be all right for the weekend, whereas the outcome of Jack's scan was ok. We hope to have him back as soon as possible.
"Danny's injury may be a little bit different. He hurt his groin right at the end of training, funnily enough, when we were practising our set pieces, so he will be out for a little while."