The club’s pre-season period was disrupted by injury and unavailability and Rutherford is being realistic in what can be expected of the players in the opening few games.
They lost their latest friendly 3-0 at Bognor on Monday but were without key players Lloyd Rowlatt, Scott Jones, Corey Heath, Connor Cody and Ryan Davidson.
Most or all should make Saturday’s Isthmian south east opener at home to VCD, but City have lost two of last season’s squad – winger Josh Clack to Haywards Heath and keeper Steve Mowthorpe to AFC Portchester.
Rutherford said: “It’s been a very stop-start pre-season and a number of our players have hardly played.
“I don’t think you’ll be able to tell much about our season until September at the earliest, but once we have had everyone available for a little while we will be okay.”
City have yet to play a completed season at step four of the non-league pyramid and Rutherford knows it will be tough to replicate the campaign they had in the truncated 19-20 season, when they looked like they might snaffle a play-off spot.
But he said: “We have a happy camp and we have kept most of last season’s squad, and we have some good youngsters from the U23s and U18s pushing for a chance.
“Graeme (Gee), Danny (Potter), Dabba (Killpartrick) and I are looking forward to the challenge ahead.”