“You blow your whistle and then, all of a sudden, voom, you have 20, 30 people standing to attention,” says Jason McCarthy, discussing his transition into coaching after retiring from playing aged 29. He put on his first sessions while a defender at Wycombe, taking the club foundation’s under-16s. “I was so flustered. I learned very quickly: if I’m going to do this in front of men – hopefully, eventually – then I need to practise.”

He accepted the role of Brighton’s under-21s assistant at the start of last year and recently returned to the role after two months in interim charge this summer, while the head coach, Shannon Ruth, supported Fabian Hürzeler’s first-team staff. McCarthy has huge admiration for Hürzeler, Brighton’s impressive 33-year-old head coach who at 31 became the youngest permanent manager in Premier League history and was part of his interview process.

“It was the first interview I ever went for,” recalls McCarthy. “He asked me a lot of questions: ‘How do I see the game? What sort of teams do I watch? When did I realise that I wanted to be a coach?’ He retired at 23, so he was really empathetic: ‘It’s scary, it’s daunting, people will tell you to keep on playing, but trust the feeling you have.’”

Brighton, third in the top flight before visiting Sunderland on Saturday after a flying start, are frequently referenced as a model club. McCarthy chuckles as a moment that speaks to Hürzeler’s “incredible growth mindset” crosses his mind. “I saw him running around the training ground, holding a piece of paper and reading. I think he read somewhere that taking on information while exercising can help you remember it. He’s constantly trying to improve himself. How can you not be inspired by that?”

Across an hour in McCarthy’s company, his passion for the role and joy at helping others prosper becomes apparent, as does his gratitude to Brighton for giving him the opportunity to express himself as a coach. Before he joined, their approach fascinated him from afar. “I thought: ‘These guys think differently. They don’t just go tried and tested. They might listen to a 29-year-old who’s potentially retiring.’ Brighton, in my opinion, are the most forward-thinking club in the world.”

He cites Mauricio Pochettino, who he saw work first hand at Southampton, as another source of inspiration. McCarthy made 301 career appearances across the top four divisions, one of those coming in the Premier League when Ronald Koeman handed him his Southampton debut as an 87th-minute substitute at Crystal Palace on Boxing Day in 2014. “The quickest bib-to-shirt change you’ve ever seen. I was on the right with [Sadio] Mané ... crazy. Koeman was a lot colder than Pochettino, but a very good coach. He’d make me feel terrible; he liked joining in drills – he was in his 50s but he’d never lose the ball and here I was, couldn’t trap a bag of cement. Even at that age I was curious about coaching and management styles.”

McCarthy, 31 next month, tells a lovely story about Pochettino at Southampton. He was 17 and cleaning José Fonte’s boots when he felt an arm on his shoulder. “It was the gaffer. He said: ‘I watched your game for the under-21s. I thought you did this well, you could have done this better, so, next week, you’ll train with us and we’ll work on some of those things.’ I went out for training on the Monday, I was right-back in an 11 v 11 and the manager is stood right behind me. They would’ve just had a big Premier League game but he was talking me through what he wanted. I felt like he knew me inside out, and I was just a scholar; he made me feel 10ft tall.”

It was McCarthy’s friend Tobi Sho-Silva, a former Charlton trainee now of Hampton & Richmond Borough, who encouraged him to get the ball rolling on his coaching badges. McCarthy was 26 and, until that conversation, he had other ideas. “I’m a man of faith, so I thought maybe I’ll end up being a pastor or working within the church. But then I did my [Uefa] B licence and I knew after about a week that I was way more suited to coaching than I was playing. It snowballed from there.”

McCarthy began putting his thoughts on paper and studying peers. He completed a diploma in psychology and a course in data analytics. He observed games live and remotely, regularly pausing matches to record interesting nuggets. He explains his intrigue in watching Barcelona under Hansi Flick, Michael Carrick’s work at Middlesbrough and Jim McNulty’s in non-league with Rochdale. “There’s a link between them – possession – but they do it in different ways. I always wanted to play in a team that played good football but I wasn’t ever good enough, to be honest. I worked under some coaches who would say: ‘This is how we want to play.’ And then in the week we would do nothing geared towards it and just expect it to show up on a Saturday.”

Coincidentally, one of McCarthy’s final appearances came against Brighton under-21s in the EFL Trophy, against players he now coaches. His last game was in the same competition in December 2024. By then, he long felt he was making a bigger impact coaching than playing. How quickly did that dawn on him? “I was probably about 27. I had a quite serious chat with my wife and my mum and dad. I said: ‘I feel bad because I know a lot of people would love to be in my position. Do I need to park coaching and come back to it?’ I had teammates and coaches telling me: ‘Relax, you’ve got a playing career to finish.’ But it’s one of the best decisions I’ve made.”

McCarthy reflects on his playing days with pride – they took him to Wembley three times and he walked out as captain with his kids there – but is determined to take further strides on the sidelines. He plans to apply for his pro licence next year. “I want to challenge myself at the elite level – I’d love to do that one day. I’m very fortunate I’m at an elite club, so I get to see elite behaviour, standards, traits, players and staff, daily. What I did as a player … can I be even better as a coach?”

Brighton’s under-21s, who last month overcame Paris Saint-Germain, were Premier League 2 champions for the first time last season. “I was incredibly proud to be part of a side that created history for the academy,” McCarthy says. “I believe winning and development come hand in hand so to help create that winning mentality within the group is something all of the staff can be really proud of. Hopefully it is just the start.” Stepping up to lead the team, he says, “has lit the fire for me to keep pushing and progressing within my coaching career”.

His faith keeps him grounded. “It’s part of my identity,” McCarthy says. “I pray before games, I read the Bible daily. I wouldn’t be where I am today without God. A big reason I’m so excited about the future is my faith, because when I started on my coaching journey, did I think that in my first interview, I’d be standing across from Fabian Hürzeler? No ... how is that even possible?”