That moment of rejection sent him on the scenic route to the top flight, via Gillingham, before spending five years at Wolves.
"It was probably the best thing that ever happened to me," he told the Daily Mail.
"It made me stronger. It's tough to be told at 16 that you won't make it and it makes you work that little bit more. It's not lost on me that I'm now at West Ham after starting off at Millwall.
"The lads have helped me settle in quickly as a member of the club and it was good to get that first goal out of the way. Hopefully I can chip in with a few more."