Liam Cooper will captain Chesterfield in the absence of skipper Sam Hird.
Hird will begin a two-match ban on Saturday after receiving his 10th yellow card of the season during the 1-0 defeat at rivals Rotherham last weekend.
Spireites boss Paul Cook told reporters: "Liam Cooper will captain the team. I think he's been very much an inspirational type lad since he came in.
"He's very much a leader in what he does on the pitch, you know, and he'll be given that opportunity on Saturday.
"It's a huge honour for any lad to be the captain of this club."
Cook has promised changes after such a poor performance at the New York Stadium.
He added: "There will be changes. You can't put up with performances like that. We let a lot of people down last Saturday."
Defenders Richard Brindley and Conor Townsend and midfielders Craig Clay and Mark Randall are among those players who will come into contention for starting roles.
Ivorian striker Armand Gnanduillet has an abductor problem and may miss out while winger Tendayi Darikwa is around two weeks away from a return as he recovers from a double hernia operation.
Leading scorer Danny Kedwell has a chance of returning for Gillingham.
The striker, with 12 goals to his name this term, has made a much quicker return to training than expected following his hamstring injury but manager Martin Allen remains wary of rushing him back too soon.
Andy Frampton was forced off carrying a knock just after the hour mark in last weekend's 2-1 victory over Dagenham and continues to be monitored, as are a few unnamed players who have been struggling with a virus this week.
Midfielder Charlie Allen (wrist) is not yet ready to return.
The Gills go into the clash two points ahead of second-placed Port Vale but nine clear of the play-off places.
