Day, 17, made his first-team debut in the Lilywhites' 2-1 victory at East Grinstead on Saturday when goals from Ashley Miller and Jamie Maxted earned Town the win.
After the game, he said on Twitter: "I'm buzzing to have made my first Isthmian League start at 17 today for Faversham Town. A great win to end the season."
He is joined in the side by former Faversham players Ira Jackson and Jack Steventon.
Also in the team is Gillingham's Barry Fuller, Stuart Lewis, of Dover Athletic, and Margate frontman Tobi Sho-Silva.
Pictured is Jack Steventon