Football matches often hinge on split second decisions. Life operates in a similar way. When Jermaine Jenas returned recently to the troubled streets of his native Nottingham, one of the BBC’s brightest new talents relived the moment his teenage self could have chosen a very different path.

“It was Friday night, at a party with my friends,” says the former England midfielder turned Match of the Day pundit. “They were all smoking weed and I was with them. I was 14. I used to play for City Boys on Saturday morning, for my local team on Saturday afternoon, and for Nottingham Forest on the Sunday. In my head, I felt like, I can’t be bothered this weekend. I turned to my mate and said, ‘Give me some of that.’ He looked at me and said, ‘No, you’re not having any, you’ve got a game this weekend.’” He exhales. “He’s my best friend to this day. We still laugh about that night. It could have been the moment when it all went under.”

Instead of sinking, Jenas rose. After impressing at Forest, at 18 he signed for Newcastle for £5m, and spent the next decade playing at the top level, earning 21 caps for his country. Since his retirement in 2014, he’s become a coolly authoritative analyst on MOTD, MOTD 2, and Radio Five Live. None of which, he discovered, cut much ice when confronting Nottingham’s territorial teen gangs for a new documentary on knife crime, BBC3's Teenage Knife Wars.

“You find out pretty quick that they don’t really care who you are,” he says. “They’re in their own world, almost dead behind the eyes. The first interview I did was the middle of the night, in a wasteland. The lad was 15 and at school, but he was six foot two, with a Balaclava over his face. I thought, this could go either way! Other kids I met had swords and machetes. I didn’t want to talk down to them as an ex-footballer who lives behind electric gates and has an easy life. It wasn’t about that. I’ve still got family from these areas.”

Concerned by a recent sharp spike in incidents of knife crime in his home city, Jenas embarked on a very personal odyssey. As a father, he was deeply affected by the testimony of a mother who had lost her son. During filming, a double murder occurred in Sneinton, on the street where his own father once lived. “It was mad. Twenty-five years ago, I used to run up and down this street, playing football with my dad, and now I’m looking at a shrine to two men, because of knives. I went through a lot of emotions: sadness, anger, frustration.”

His own adolescence featured “minor incidents” of criminality. “I got robbed at knifepoint at a barbershop by a gang. At the time, I was angry at them, and angry at my city, but the older you get the more you develop an understanding.

"I’m not condoning it, but these kids are caught in bad situations around bad people, and before you know it bad things happen. People I knew went down that road, and often it didn’t end well. People I know have been to jail. The blessing I always had was that I had a focus. These kids feel they have nothing to lose. I went through my entire youth feeling I had everything to lose, because I knew I had a talent. It was drilled into me. The weight of trying to get my family out of the situation we were in was on my shoulders.”

Jenas’s parents divorced before he was ten. His father Dennis, a coach with Nottingham Forest, later moved to the United States. “I became the man of my house very quickly,” he says. “I was basically paying the mortgage at 15. Luckily, I enjoyed that weight of expectation.” As a young, successful black man, he’s mindful of his responsibilities as a role model. “My dad and mum were very strong on, ‘Jermaine, there’s not enough people that a young black child can aspire to be.’ I’m aware of that, but I didn’t go searching for it.” 

At 34, having served an apprenticeship with established anchor men like Gary Lineker and Mark Chapman, the documentary marks Jenas’s debut as a presenter. It’s unlikely to be his last.

“It drew things out of me I didn’t expect to feel,” he says. “Punditry is great, but when you find yourself talking about game after game after game, after a bit your mind goes numb! It’s like being asked to get out a crystal ball, and the minute you get it wrong everyone’s on your back. The film reenergised me. I’m very proud of it. I hope there’s more. I want to get into presenting. I watch Gary and Mark, and they’re both great, in terms of trying to help me.” 

His own future looks bright. The future of Britain’s angry, alienated teens is more complex. “We need to be stronger to deter people from carrying knives, but also offer some hope of change. The elder gangsters are looking for the abandoned child. It’s a grooming thing. If we don’t look after these kids as a society, somebody else on the other side of the fence is more than happy to take them on.”

Jermaine Jenas's Teenage Knife Wars is available to watch on BBC3 and BBC iPlayer