Ahead of Non-League Day on 13 October we spoke to Premier League footballers who played in the non-league game before their rise through the football pyramid.
Bettinelli arrived at Princes Park as a 20-year-old in August 2012 and spent most of the following season playing in what is now known as the National League, or the fifth tier of English football.
Some of his colleagues helped him to grow up, while others nurtured his self-belief.
"Lee Burns was an absolute tank," says Bettinelli. "It was my first real taste of men’s football and he was at that time the biggest man I'd ever seen.
"Tony Burman, who was the manager at the time, gave me my first chance in football at men's level and stuck with me through the whole season. He's someone I’ll always remember.
"There was a goalkeeping coach too called John Macrae. He always used to say to me, 'You've got great potential, you can go all the way.'
"At the time I was only a young boy and I used to dismiss it. But he’s always believed in me and he comes to the [Fulham] games now sometimes.
"He’s someone I’ll always think back on and think happy thoughts about from when I was back at Dartford."
Bettinelli has gone on to become a Premier League player, helping Fulham to promotion last season, and earned an England call-up last month.
His affection for the Kent club is shown by him maintaining close ties, such as meeting his former team-mates at Millwall when Fulham went there in the Carabao Cup.
"They came down and watched the game and I met them at half-time," says Bettinelli, who was rested for the match. "I had a good chat with them.
"I’ve got fantastic memories of when I was there. I went back last season to watch a game.
"It’s a fantastic place to go and of course it's great to see fans who remember you from when you played there."
For more on Non-League Day 2018, go to nonleagueday.co.uk.
Part 1: Foster: Traffic jam gave me my big break in non-league
Part 2: Barnes: Non-league was central to my development
Part 3: Arter: Non-league coach restored love of the game
Part 4: Cook: Non-league game did me the world of good