He was delighted when Hong Kong's reigning champions, South China, told him they wanted to sign him during the 2009-10 season.

But the transfer was halted because of a rule that prevents teenagers aged 18 or under who have played in the elite youth league from changing clubs before becoming adults. 'At that time, South China were expanding their squad because they were playing in the Asian Football Confederation Cup that season. I knew it was my one and only chance to become a full-time footballer,' Chan says. 'I was so frustrated that this obscure rule would stop me realising my dream.'

The next season he joined Second Division side Sha Tin and weighed up his career options. 'I had a very long chat with my father last year,' Chan says. 'He gave me great, impartial advice. I decided I needed to learn a profession and picked a three-month training course run by the Construction Industry Training Board. I thought it was a good idea. It offered daily subsidies and taught me a skill.'

Chan also wanted to earn a salary so he could contribute to his family's income - and help bring up his little sister. 'I didn't have any real goal in life before, but the birth of my younger sister six years ago focused my thinking,' he says. 'I saw her growing up and realised I should contribute to my family's income - and not just be a burden to my father; he's the only person with an income. I wanted my sister to have a better life.'

Last May, he began learning to be a builder, using timber and aluminium. He now works four to five days a week. Since September, he has played part-time for Second Division side Happy Valley Athletic Association. He says: 'I like my job. It gives me a very flexible working schedule so I can spend my weekends training and playing in matches.

'When I started that, I was really tired at the end of each day and so lacked the energy to play at my best on the football pitch.'

Yet after a few months' work on the building site, Chan began to pace himself. 'Like sport, building involves a lot of teamwork. When I got to know how my colleagues worked, I learned to adjust my efforts and speed up when needed, instead of rushing unnecessarily all the time.' As Chan got used to his working life, and stopped wasting his energy, his performances on the football pitch improved.

Chan still dreams of being a footballer, but his job has helped him become realistic - and also gain new insights into building design and construction.

'I hope after a few years I'd be good enough to share my experiences of working on building sites with students taking the board's training courses,' he says. 'I've changed my thinking. I hated studies before. Now I want to use my savings to further my studies. I hope to take a degree in architecture one day so I can work on building sites - but in a new role.'