Just four weeks after the Gills triumphed in the League Two play-off final at Wembley, Simon King, Gary Richards, John Nutter, Stuart Lewis and Luke Rooney came in for a training session with fitness coach Danny Ellis, a week before pre-season is due to start.
"The session was completely voluntary so it's great to see that the lads haven't lost their appetite," Stimson told the Gills' official website.
Stimson was also pleased with the progress that Nutter has been making following surgery to repair a hernia problem.
He added: "Nutter's already flying in training. Hopefully he'll have no reaction and we'll have him back in time for pre-season."