Darren Oldaker made his Gillingham debut on Saturday.
The 17-year-old midfielder came off the bench with 15 minutes left, replacing Emmanuel Osadebe.
Boss Justin Edinburgh had earlier introduced fellow teenager Elliott List, for what was only his sixth appearance.
Gillingham were already four goals down by the time Oldaker made an appearance and they conceded a fifth soon after.
Boss Justin Edinburgh said: “It was a tough call but I felt he had no fear, nothing to worry about.
“He and Elliott List went on and gave a fantastic account of themselves.
“I was pleased with them both. They were bright sparks out of a really disappointing afternoon.”
Oldaker was a regular in the team during pre-season, having been handed his first professional contract in the summer. He had been an unused substitute for Gills’ first four games.
He tweeted: “Such a shame about the result but a massive positive to take out making my debut for the Gills.”