The 18 year old told The Sun: "My senior school didn't play football. It was a rugby and cricket school and as I was on a sports scholarship I was forced to play rugby.
"I played scrum-half or full-back and I was all right at it. I got a trial for London Irish but couldn't do it because Southampton wouldn't let me."
The teenager, who scored in Arsenal's Champions League win over Olympiakos, said dad Mark - a former England international - kept him grounded.
He added: "He'll watch me play and, if I've done well, he'll have a quiet word with me and say, 'Well done'. If I've had a not-so-good game, he'll let me know about it."