Tom Broadbent leans across the table at a coffee shop in Bristol, stretching out the huge, muscular frame that impressed a few Chelsea players a couple of months ago, and casually tells the story about the time he was shot at in Afghanistan while listening to the Red Hot Chili Peppers.

It is quite a tale, even if Broadbent’s unassuming, laid-back demeanour suggests otherwise, and forms part of a fascinating and colourful story that includes handing over FA Cup medals in the royal box, working behind the hot food counter in Sainsbury’s and filing an entry for “Speedo fan of the year” via a photograph on social media. “Bloody hell, you have been digging around,” Broadbent says, breaking into laughter.

Now, at the age of 25, a new chapter is waiting to be written for a man who looks as if he could teach Cristiano Ronaldo a thing or two in the gym. Weighing 90kg and 6ft 3in, Lance Bombardier Broadbent is leaving the army behind to embark on a career as a professional footballer after signing for Bristol Rovers. “This is what I’ve always wanted to do,” he says, smiling. “It still hasn’t sunk in yet that I’ve got the chance.”

Although technically a soldier in the Royal Artillery until 4 September, Broadbent is thankful to the army for giving him the green light to grasp an opportunity that came about through a combination of talent, perseverance, useful contacts and teach-it-yourself video-editing skills – not to mention a leap of faith on the part of Darrell Clarke, the Rovers manager.

Broadbent, who was captain of Hayes and Yeading United in the Southern League Premier division last season, takes up the story. “The UK armed forces manager is Nick de-Long and he mentioned he could try to help me out,” Broadbent says. “Nick’s good friends with Tommy Doherty, who played with Danny Coles at Bristol City. Danny’s an agent now, and that’s pretty much how it all started.

“Nick asked me to send him a video – I had all the footage of the games so I just put it together myself. It’s 13 minutes long, basic, but it gets to the point. The morning after I sent it to Nick, he phoned me back to say: ‘You’ve got a trial.’”

Clarke, who has never had any qualms about delving into the non-league game to recruit players, was even more impressed when he saw Broadbent in the flesh. An imposing central defender with a decent left foot – take a look at the footage of a curling 25-yard free-kick that found the top corner against the Royal Navy in March – Broadbent convinced the Rovers manager across 10 days of pre‑season training and two friendlies that he deserved a contract.

That Broadbent had the physical attributes was never really in doubt. “There’s been a few jokes made about that,” he says with a wry smile. “We do a bit of circuit training in the afternoon during pre-season and no one wants to pair up. I tend to just grab someone and say: ‘You’re with me.’ They’re like: ‘No I’m not!’”

Tom Broadbent says of his time in Afghanistan: ‘I was excited when I first found out I was going. Anyone who joins the army, they want to go on tour.’ Photograph: Tom Broadbent

As the laughter passes, Broadbent looks himself up and down and makes a serious point. “It’s the army that has done this,” he says. “I was quite small and fat when I was younger and never the fittest – a bit of a late developer really. Back then football didn’t work out – I had trials with a load of clubs – and so I got into a few jobs. I worked in Sainsbury’s serving chickens and then I did some labouring and a bit of carpentry before deciding I wanted to join the army at the age of 19.

“I don’t know why I joined; it wasn’t something I was interested in when I was younger. But I worked on my fitness to get in and went through all the basic training, so I didn’t really kick a ball for a while. Then I started to play a little bit for the regiment, went straight into the army team after that and fell in love with football again.”

It was only two years ago that Broadbent started playing semi-professionally, when he joined Farnborough, who were in the seventh tier at the time. “Up until then I’d just been playing in the army and a little bit of county league with my mates, just for the love of playing. I wasn’t bothered about getting money,” he says. “I remember the manager at Farnborough wasn’t even sure he would sign me. He did a Google search and said: ‘You’ve never been anywhere.’”

We came under fire a couple of times. Luckily I was in an armoured vehicle so I didn’t care too much. It’s a bit surreal

That was true in one respect but not in another. Broadbent has been to most places, including a posting to Ascension Island – a remote outpost in the South Atlantic that is 1,000 miles from anywhere – and Afghanistan, where he spent five months in 2014.

“I got to Afghan at the end of it and luckily it wasn’t a nasty tour for me,” he says. “To be honest, I was excited when I first found out I was going. Anyone who joins the army, they want to go on tour. I wouldn’t want to have left the army without having done that because it’s the first thing someone asks you: ‘Have you been anywhere?’

“But when my mum and my missus found out I was going, they weren’t happy at all. It’s probably worse for the people back home than it is for the person out there, certainly emotionally – they’re worrying whether you’re safe. Not that I’m a soldier that was necessarily on the frontline or anything like that. Yeah, I went out on the ground a few times, but I’m not an infanteer – they’re the proper heroes who go out on the frontline on a daily basis.

“My job is quite straightforward. In Afghanistan I was working with something called Desert Hawk III, which was a little spy plane [an unmanned aircraft], so we’d go out attached to the infantry, find a nice little safe spot for us, they’d go in and do their patrols and we’d throw our plane up and watch over them, telling them what’s going on ahead of them.”

Tom Broadbent, right, in action for Bristol Rovers during a friendly against Hull City. Photograph: Stephenson/JMP/Rex/Shutterstock

In a run-of-the-mill way, Broadbent adds: “We came under fire a couple of times. Luckily I was in an armoured vehicle so I didn’t care too much. It’s a bit surreal, really. At the time I was sat in the back of the vehicle listening to some music and one of my mates tapped me and said: ‘Did you hear that?’ And then you just hear the rounds pinging off the vehicle. I quickly put my headphones back in. I can even remember what song I was listening to – Scar Tissue by the Red Hot Chili Peppers. Quite fitting, really.”

Three years later the soundtrack was Abide With Me in the rather more comfortable and relaxed surroundings of Wembley Stadium, where Broadbent’s mission was to get his hands on the FA Cup rather than the enemy. It was an opportunity that came his way because each of the three services that make up the armed forces nominate a representative to attend the final and take part in ceremonial duties. Broadbent “sort of fell into it” after his friend was unable to attend May’s showpiece between Chelsea and Arsenal.

“I thought I’d get on TV but they were interviewing Arsène Wenger at the time I was handing the runners-up medals to the royal box, so I missed out,” he says. “But it was a really good day and I got to meet a few of the players. I remember they made some comments. ‘Look at the size of you!’ Ruben Loftus-Cheek said when he saw me on the sideline. He was like: ‘Bloody hell’, and he started squeezing my biceps. I was like: ‘All right, mate!’”

By that stage Broadbent had notified the army of his desire to leave after concluding it was now or never in terms of trying to take his football career further. “I made a decision in February – and it’s quite a big decision because when you’re in the army you kind of feel there’s not a lot else out there for you to do. On the flipside, there’s so much that you can’t really decide, so you end up staying in. But I went to see my troop commander and said: ‘I want to sign off.’ They were surprised because I’d done quite well in the army. But I said: ‘I’m going to go for it. I want to play pro football.’”

It was a gamble that has paid off much quicker than Broadbent could have imagined as he prepares to follow in the footsteps of Maik Taylor, Guy Whittingham and Lee Bradbury, all of whom served in the army before playing professionally.

Tom Broadbent at last season’s FA Cup final. ‘I thought I’d get on TV but they were interviewing Arsène Wenger at the time I was handing the runners-up medals to the royal box, so I missed out,’ he says. Photograph: Tom Broadbent

Broadbent acknowledges it is a big step up on paper as he contemplates playing in League One, yet there is a quiet confidence about him that he admits he never had as a child.

There is also no shortage of motivation when he thinks about everything he has been through to get this far.

“This definitely means more to me than others. I’ve got life experience. I’ve been there when I’ve been struggling, getting moaned at behind the counter at Sainsbury’s because the chicken wasn’t ready. I haven’t got to worry about that any more, standing there with my hat and apron on, or when I was labouring and at the bottom of the pile, getting all the rubbish jobs.

“And then obviously there’s good times in the army but tough times as well. Coming out of there and going into football – I’m 25 and I’d almost got to the point where I thought maybe it’s not going to happen for me. Now it obviously has and I’m just really grateful for the opportunity.”