The Waterlooville fighter, 24, had limited his gym time to just one session a week for periods while he was training and made a scoring debut in his one and only appearance for City of Portsmouth Sunday League side The Falcon.
After turning professional in 2019, Chamberlain had won each of his opening three fights - all of which had arrived the space of just eight months – as he made a promising beginning to life as a lightweight following his move up from the amateurs.
Yet his pro career, along with so many up and down the country during the height of the Covid-19 outbreak, came shuddering to a halt.
Regularly making the trip from his Waterlooville home to work in Worthing then racing to make sessions with trainer Wayne Batten at his Southampton gym was becoming a strain – particularly with no fight on the horizon.
But Jamie explained how a trip to leading promoter Frank Warren's HQ with brother Mark - himself a promising fighter with a 9-0 pro record - to sign a contract extension were when his fortunes took an unlikely turn for the better after months of frustration.
‘I just felt like giving up. Obviously I fight in March and the last time I fought was just over two years ago - December 2019 was my last fight,’ said Jamie.
‘I even started playing a bit of football. It was just Sunday League, really, we would train on a Wednesday and games were on a Sunday. I only played one game then about a week later I went with my brother (Mark) and my dad to renew Mark’s contract. My dad spoke to Andy Ayling (part of Frank Warren Promotions team) and we sat down, explained (the situation) and two days later a contract came through for a three-year deal.
‘I train five days a week and I’m just loving it now. They knew I was Mark’s brother (Frank Warren’s team) but they didn’t know I did boxing, my dad explained to them - it took them three years to know that I actually did box!’
Certainly, it proved quite the upturn for Jamie who will have his fights on promoter Frank Warren cards televised on BT Sport.
His ring return is now just a few weeks away, with a bout at his new featherweight to come at York Hall against Ricky Starkey on March 11.
But Jamie admitted it will almost feel like he is starting all over again in the sport first took up aged seven having been out of the ring for more than two years.
‘Without the pandemic I would have had a lot more fights, but it is what it is. It’s kind of like having my first fight again where I haven’t boxed for so long - that’s what it feels like,’ he added.
‘It’s just trying to get back into it, have a few fights, and see where it goes from there once Frank and that see what I can do.’
But promoter Warren's gain is City of Portsmouth Sunday League side The Falcon's loss. ‘I scored a last-minute header and we drew 3-3 (in his first and only Sunday League appearance). We were in stoppage-time and after the corner I headed in the whistle went so we drew 3-3,’ revealed Chamberlain.
But now the football boots are firmly back in the cupboard as he looks to have just the same impact he did for The Falcon on his upcoming ring return.