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Instead, now 41, he provides free classes to hundreds of young people at his Nottingham School of Boxing, with some of his charges even harbouring dreams of reaching the Olympics.
His work has won him the BBC East Midlands Get Inspired Unsung Hero award for 2016, and he will now be among the finalists for the national competition, with the winner to be announced at the BBC Sports Personality of the Year ceremony on BBC One on Sunday, 18 December.
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"I was brought up in an area of deprivation and my role models were people who were involved in crime. I got myself into gangs and I was going down the wrong pathway," he told BBC East Midlands Today.
"I've seen people like me who were lost and thought that they were stuck in this bubble where you've got a criminal record, so you can't get a job.
"You try to get a job, you can't get a job so you go back into crime again, this vicious circle. So I thought, you know what, I want to break this."
Baz, who was praised by the judging panel for his "immeasurable" impact on breaking the cycle of crime, commits 30 hours a week to provide boxing classes, transport to competitions, and to teach valuable life skills.
Having seen his career ended in a violent incident, he holds training sessions in areas with rival gangs to try to prevent more conflict.
"While I am working with them, I am integrating the young people with each other," he continued.
"By the time they get to an age where there could be conflict, they actually know each other.
"We are giving kids an opportunity to aspire to do phenomenal things."
Bryer Wheatley, who became English national champion in the Class B under-54kg category as a 16-year-old in 2014, is one of those the coach has helped.
"Baz has got me into college, got me a part-time job and really put me on the right track," he explained.
"I have even become a national boxing champion, and have aspirations of going to the Olympics one day.
"If it wasn't for Baz, my mum and dad would have thrown me out and I would have ended up in prison."
Marcellus Baz and Bryer Wheatley were speaking to BBC East Midlands Today sports editor Natalie Jackson
Having seen his hopes of a professional boxing career ended at the age of 23 when he was stabbed through the hand by a rival gang member, Marcellus Baz could have carried on down the wrong path.