Forward Sproule, a summer signing from Hibernian, will miss promoted City's first four fixtures of the new campaign through suspension following his disciplinary problems with the SPL side last season.
However, fellow new arrivals Stephen Henderson, Michael McIndoe, Tamas Vasko, Lee Trundle and Marvin Elliott are all in contention to make their debuts for the club in their first game at this level since being relegated in 1999.
Chris Weale and Jennison Myrie-Williams have temporarily left Ashton Gate to undertake loan spells with Hereford and Cheltenham respectively.
QPR meanwhile are set to be without six players on Saturday.
As well as summer signing Simon Walton, who faces six months on the sidelines with a broken leg, defender Pat Kanyuka (thigh), winger Gareth Ainsworth (fractured fibula) and forward Ray Jones (foot) will also be missing at Ashton Gate.
Physio Paul Hunter said: "Ray has had a tough pre-season, with ankle and foot injuries, while Gareth is making steady progress from his leg fracture.
"Pat will be out of action for some time, after he had an operation to fix his torn thigh muscle."
Defenders Chris Barker - a summer signing from Cardiff - and Sampsa Timoska are also out as they must serve three and one-match suspensions respectively
But Gregory is expected to hand debuts to some of his other summer signings, who comprise goalkeeper Lee Camp, defender John Curtis, midfielder Daniel Nardiello and forward Ben Sahar, who is on loan from Chelsea.
Sporting Life