A sprightly 61-year-old ("but I don't feel it"), over the years Bryn has trained hundreds of youngsters - from the naturally gifted to the technically challenged, as the school is open to all abilities. Foremost among the first is Manchester United's flying winger Ryan Giggs, who went from pint-sized prodigy to tormentor of Premier League defenders.
"I first saw him play at the age of 10," recalls Bryn. "And it was obvious, even then, that he had something a bit different. I was coaching Salford Boys at the time. Ryan was at a junior school in Swinton where a cousin of mine was teaching. She told me they had a lad who looked a really brilliant little footballer.
"I went to see him. He was a slip of a lad, and very frail looking. But he was exceptionally fast, well-balanced and tremendously skilful.
"He was never conceited. He was a good learner and would always listen. He just loved playing and was determined to become a professional. It was lovely to see him play because he had such natural grace."
Bryn himself had trials for United as a teenager and then played at centre-half for several top amateur sides in the north-west. "I trained a lot by myself so it came naturally to me to work out training sessions for the rest of the team based on what I thought was good for me."
At the age of 26 he became a PE teacher and set about creating converts to the "beautiful game". And it wasn't long before he obtained his full coaching badge from the Football Association. Bobby Charlton headhunted him 18 years ago.
"He came back from the Mexico World Cup determined to try to do something for youth football. He had seen kids in Mexico performing brilliant ball skills with oranges or rolled-up newspapers, doing amazing tricks. And he thought 'if these kids can do it, why can't ours?' "When we started it was quite hectic. We used to think that if we got 30 children, then we could start to make it pay for itself. But it became so successful in such a short space of time that we had 200 kids turning up every week."
He says that kids in this country are becoming more and more technically gifted. "The biggest problem is that in our game you have to perform these skills at a much higher speed than in Italy or Germany. Our grounds encourage that type of football because they are so compact that the anxiety of the crowd transmits itself more easily to the players."
Last year children from 20 countries attended the Summer camps. "It's like the United Nations," says Bryn. "We've got kids here from the estate over the back mixing with kids from Tokyo. But football goes beyond the language barrier. "
The soccer school's main site, Hopwood Hall, is a sixth-form college most of the year round. Come summer, goalposts, cones and life-size cut-outs sprout from the parkland and the place teems with kids practising free-kicks, playing five-a-side or foot-volleyball (no hands allowed). Each week, around 400 children aged from 5 to 18 take part in programmes ranging from fun courses for the youngest (Fred's Little Devils) to serious training for teenage potential pros. There are language classes for foreign students, visits to Old Trafford and nights out in Manchester. Big names from the north-west's leading clubs are frequent visitors ("It's like a Who's Who of football some days") and so is the man himself. So what's it like having a living legend for a boss?
"Bobby is great. He comes down most days and spends some time with each of the groups. The kids love it. He'll sit and have lunch with them, chatting and doing tricks.
"When you are abroad and you mention you're from Manchester, they will always ask if you know Bobby Charlton. It's incredible the affection people have for him. But he's a humble man and very unaffected by it all."
Bryn was technical adviser on the Channel Four series Ryan Giggs' Soccer Skills, which became one of the top-selling videos last Christmas. He's since been recognised in the street but he's keeping his feet on the ground and his eyes on the ball.
"I just love coaching football. Whether it's with boys, or girls, or adults, I enjoy it just as much. It's the easiest game in the world to play. You can practise by yourself - all you need is a ball. Then with a few mates and coats for goalposts, you've got a game. And it's a marvellous game."