McCall's resources have been stretched for the opening six league games of the season due to a number of absentees but the City chief believes he will have more options available to him for the fixture with the Gills.
After missing last Saturday's match at Millwall due to international duty, Josh Cullen is available once again for selection.
Deadline day loan signings Marc McNulty and Haris Vuckic are also expected to be in City's travelling party for the match at the MEMS Priestfield Stadium.
James Hanson will be assessed pre-match to see if he has any chance of being involved after returning to training on Thursday.
Tony McMahon also joined in with training for the first time following a recent thigh injury but this Saturday's game could come slightly too soon for the right back.
Rory McArdle is expected to feature in next Tuesday's reserve match at Hartlepool United, while fellow central defender Nathan Clarke is in line to make his own return to training on Monday.
Speaking about his squad options, McCall said: "We've been to Peterborough United, MK Dons and Millwall and put in strong performances. We have that belief now we can do the same and be as strong as we can.
"The one difference now is that we have plenty of bodies back - the squad will be stronger.
"We were slightly disappointed at Millwall last weekend that we didn't manage to get the win but a point is still a very strong result, especially considering that we didn't have the options from the bench to change it much.
"That will certainly be different at Gillingham though - we will have more options.
"It was good to get a chance to see Haris (Vuckic) in action in the reserves at Burton Albion on Wednesday. The game was also the first full ninety minutes of the season for Killa (Matthew Kilgallon) and Fil (Morais).
"Josh (Cullen) travelled back (from international duty) on Wednesday and he trained with us today (Thursday). He is raring to go and he adds himself to the group of players who come back after being unavailable last Saturday.
"Haris and (Marc) McNulty are also available to us having missed the game at Millwall.
"(James) Hanson and (Tony) McMahon have trained today for the first time so we will see how they react to that tomorrow before we travel.
"Either way, we will definitely have a stronger squad and options from the bench.
"Rory (McArdle) is back in full contact training this week and hopefully he will play in the reserve match next Tuesday.
"Nathan (Clarke) is out running and he looks like one we can welcome back into the fold next week."
In other news, City striker Reece Webb-Foster has joined National League side Guiseley on a one-month loan deal.