On a wall in a plush city centre office, a framed, bright red banner stands out.

‘GARY NEVILLE GROW A PROPER MUZZY OR SHAVE IT OFF YER SCRUFF’, its white letters scream. It is an artefact from the depths of the mighty Kop of Liverpool.

But this is certainly not Anfield. This is the man himself’s Manchester HQ. One of six buildings he owns in a city in which he lives and breathes. The nerve centre from which the former United defender, sans muzzy these days, directs a vast empire.

‘There’s a Scouse lad who works on our podcast,’ he explains, laughing. ‘Every time I played at Anfield they’d have a different banner for me. One year they compared me to Dot Cotton off Eastenders. We were talking about this one and the lad said he thought he knew who had it, so he went and got it. I like looking at it every day - it keeps me humble.’

Mail Sport meets him a week shy of a big birthday. On Tuesday he will turn 50. A time to reflect. Not that he has much of that.

As we speak, a flatscreen TV above Neville’s seat displays sleek images from St Michael’s, a £400million, 40-storey mix of apartments, offices, a hotel and rooftop restaurant, currently rising yards away from where we are sitting.

It is the latest project, in partnership with others including Betfred founder Fred Done, from Neville’s Relentless Developments.

The company name is fitting. Relentless as a player and now in business there are hotels, a university and a production company in the portfolio. In total, he employs 700 staff.

It is a far cry from his time on the right of United’s robust defence - although if you were on a club flight home from European action in the late 90s you may have spotted a clue as to which direction he was heading.

While the likes of Dwight Yorke and Teddy Sheringham were engaging in rounds of high-stakes poker at the back, Neville was showing a glimpse of his hand further down the front.

‘I used to bring architect's drawings with me,’ he explains. ‘You have two hours on the way home on the plane. You can't sleep. You're wired. I'd make sure no one was sat next to me and I'd get them out. While Teddy and Dwight and that lot were playing cards, I’d be looking at drawings.’

Neville got the property bug at 21, when he bought a 12,000-square-foot barn in Bolton and developed it. ‘I made loads of mistakes, spent too much money, changed designs all the time,’ he explains. ‘But from rubble we made it into this house and I was obsessed.’

Going into business with a childhood friend and fellow ex-United trainee Paul Devine, 25 more houses followed over the next 10 years. ‘I’ve still got three or four,’ Neville says. ‘My mum lives in one.’

While team-mates were on the golf course, he donned his hard hat and headed for building sites. ‘For 10 to 12 years, I had this almost like double life,’ he recalls. ‘I did it under the radar, purely because I knew that it would be deemed as a distraction. 

'Under Sir Alex, distraction was absolutely illegal, you know that. But I knew that my football career would come to an end, and I knew that I had to plan for it, I knew that I had to do something different and I loved it.

'The meetings, the thrill of the interior design, the selling part of it, the finding the land, the planning.’

At the end of his playing career in 2011, Neville shifted focus from Bolton to Manchester and went public with that second life. He is clearly revelling in it, so much so that his enthusiasm leads to an unthinkable question.

Does a man who captained his boyhood club, won that treble, picked up 85 caps for his country, actually prefer the present to the past?

‘I had this thing at 36 that my second half of my life had to be better than my first,’ he responds. ‘I knew that was going to be near-impossible but I actually love my post-football career, I think even more because there was an element of playing at United which was amazing, the best thing in the world, and some of the thrills and highs were unbelievable.

'But under Sir Alex it was a tough environment in that the standards were hugely high, which meant that you had to live at that level every single day. I've got more of a consistency.

'You maybe lose those huge highs, but you also lose those big lows that you have, like losing a Champions League semi-final and all of a sudden the world feels like it's coming on top of you.’

While not running his property operation Neville is the nation’s most recognisable and forthright pundit, the man who brought down the European Super League. He is also publishing the popular Stick to Football podcast with sparring partner Jamie Carragher, Roy Keane and Ian Wright. No wonder his nickname at United was ‘Busy’.

‘George Switzer, who played with me in the youth team, gave me that when we were 16,’ he recalls. ‘He’d be like “Why are you always buzzing around?” I was always active, always hyper and I’ve always been the same.’

His ’Attack the Day’ mentality, which he puts down to a work ethic drilled into him by his parents and his upbringing at United, starts at 5.15am at the home he shares in the city with his wife Emma and their two teenage daughters.

‘I'll review all the news, sports news mainly, but news as well,’ he says. ‘All your papers. I need to keep across that. I'll clear my emails. I'll have a coffee.

'I'll go to the gym for six, finish at 6.50, walk back home for seven. And then I'll spend the hour with the kids when they're getting ready for school. I'll be in the office at eight and I’ll work through to about six o'clock. That's it.

'My phone will go away for an hour and a half while I'm having tea. I'll watch the game that night. Bed at half nine, quarter to 10. I'm lucky, I can be asleep within five minutes.’

Routine, routine, routine. ‘My whole life was routine and repetition,’ he adds. ‘Even now, I need structure. I look at my calendar four or five weeks in advance.

'I know now that for the next six weeks I'm sprinting every single day. But I also know from the 17th to the 21st of March, I've got four days where I'll go away with my wife.’

Thursday night is date night. ‘There’s no football on Thursday. Well, there is United,’ he laughs. ‘But I don’t work Thursday nights. My mum has the kids.

'We go out for a meal sometimes. Because we're living in Manchester city centre, we'll go out shopping or we'll sit in.’

He remains in shape and no longer drinks during the week. ‘I used to have a couple of glasses of wine, but you feel like s*** the next day. I just feel little changes I've made mean that I feel better now than I did five years ago.’

There are other lessons. His short stint as manager of Valencia – a favour for a friend that lasted four unhappy months over 2015 and 2016 – taught him a few.

‘Stick in your lane, stick to what you're good at,’ Neville says. ‘This idea that I thought I could have all the businesses, the media career and be a head coach was nonsense, absolute nonsense.’

Humility was another. ‘I saw Ange Postecoglou's interview recently and it really hit home when he said: “these guys are tired, they've been playing Thursday, Sunday, Thursday, Sunday for the last four months”.

'At Valencia post-Christmas, I didn't have one midweek break for three months. It was awful. I lost my confidence, didn't want to turn up to press conferences.

'Six a week, the questions the same. “When's this going to end?” All the things that I know you have to ask. It was brutal. I never ask for a manager to be sacked. It's the one job I think I stay clear of being wholly critical of.’

There are also regrets. In his autobiography, Neville described his England career as ‘a waste of time’.

‘I wouldn’t say that now,’ he says. ‘What I meant was not giving the England fans a trophy, not delivering. At United, it was winning or nothing. And with England, it was nothing. I basically played 80-odd games and never won a trophy. That's a big regret.’

It is a question often pondered – why, given the level of talent, the ‘Golden Generation’, did it not happen?

‘As a player I was anti-everybody else, siege mentality,’ Neville admits. ‘It’s United – and everyone else can do one. There was no doubt that Alex Ferguson created that and we bought into it and carried it.

'I would have absolutely despised me if I was playing against me. The idea of being despised was a trophy. I want to be despised, I don't want you to like me. I don't like you, I don't like anybody that plays for any other club.

'We were serious professionals and we were desperate to do well for England. It wasn't a lack of effort or a lack of love of playing for England.

'But maybe we missed that little bit of something that the Argentinians, the Brazilians, the Germans had. Maybe they were closer as a unit.’

That love of his club continues to run through his veins, but these are dark times on his old manor. His own trajectory and United’s have hurtled in opposite directions since he pulled on a red shirt for the last time. A startling admission underlines the pain.

‘Watching it at the moment is hard work,’ Neville says. ‘I prefer not to be given United games. That's a really bad conclusion for me to be at. As a United fan I’m thinking, “f*** it, I've got to go and do United again”.’

Neville, with his business head on, is in no doubt where the blame lies. ‘The succession planning,’ he explains. ‘When I think about it from a business perspective, what happened post Sir Alex and (former chief executive) David Gill was horrific. One hundred per cent it falls upon the owners in the Glazer family.

‘The last 10 years - to run a football club without a football department is just absolutely bizarre. How that could not be seen either by the Glazer family or by the executive that was in place is madness.

'When I left 500-600 people were working at United. That went to 1,200. How has that happened?’

There is sympathy for Sir Jim Ratcliffe and Ineos, despite a rocky start to life for the co-owners who run the show.

‘When they came in, my preference would have been for a complete takeover and for the Glazer family to leave, and it still would be because ultimately they've run their course,' he says. 'But at least there's been disruption.

'You've got to give Ineos three or four years to try and work out what the hell's going on. Six months in, they've found it bloody hard. It's an oil tanker.

'Until you're in there, you can't understand the scale of United and the enormity of everything. From keeping Erik ten Hag to the decision to bring in (sporting director) Dan Ashworth and then for him to leave, they're obviously finding it bloody tough. 

'There's no doubt that there's been turbulence and wrong decisions made. The club needs a shake. There's a lot of things that need changing.

'To be fair there’s a new CEO, new sporting director, new technical director, new CFO. You've got complete and utter transformation in six months.’

There is, however, considerably less sympathy for those on the pitch, with United 13th in the Premier League and having lost 11 times already this season. New manager Ruben Amorim has struggled, but is showing signs of putting his foot down.

‘It's got to a point whereby you think it can't go any lower,’ Neville says. ‘Ruben Amorim, I bet he can't believe what he's seeing. Some weeks you think “what the hell am I watching?”

'It is going to take tough decisions. And to be fair to Ruben Amorim, he's making tough decisions, like the Marcus Rashford one.

‘How can you play so well against Liverpool, who are the best team in the country, and then lose at home to Crystal Palace? That's the bit where I lose sympathy because that's not right.

'That's about pride, personal levels, getting up for every game. I used to call it slap yourself across the face. F***ing wake yourself up because you’ll get a shock if you’re not on it.

'Any Premier League team, whether it's now or whether it's 20 years ago, if you're one, two, three, four per cent off where you should be, they'll do you.’

Neville will play his own part, as a member of the taskforce examining the future of Old Trafford. He is of the view that a complete rebuild is the way forward.

‘It wouldn’t upset me (to see Old Trafford knocked down),’ he says. ‘I am steadfast in three things.

'Manchester United should have the best stadium in the world. They should have the best training ground and they should play entertaining attacking football. It might be arrogance, but that's how I feel. 

'I do believe it will change, by the way. One thing I'm always convinced about, and I'm steadfast, Manchester United will win again. And they'll win big.

'At the moment, I don't see that happening in the near future. But at least we've got football people in there now, who understand football.’

Unlike his former employers, Neville is in a good place as the talented former young cricketer who once shared a 236-run opening partnership with Matthew Hayden for Greenmount CC in Bury, Lancashire, approaches 50. There are issues, however, such as the increased abuse of pundits.

‘I was harassed three weeks ago at Euston station,’ he recalls of one unhappy trip to London. ‘Arsenal fan, on Snapchat, he’s walking with me, he’s got me on camera and he’s abusing me, goading me, “you’re f***ing this, you’re f***ing that”.

'It’s happening more and more and I think anger towards pundits, analysts, people on TV is getting heightened by social media. You can make a comment about Arsenal, Newcastle, whoever it might be. And all of a sudden, that fanbase is on you.

'People are trying to goad you a lot. Knowing that the minute you lift your hand, you’re getting sacked.’

Co-ownership of Salford City with the rest of United's Class of ’92 also presents challenges, not least now Peter Lim, the Singaporean businessman who gave him the Valencia job, has decided to withdraw.

‘We're currently in the play-offs in League Two and we have a good team and a good manager,' he says. 'I watch every single game. Peter was amazing. He supported us in all our projects.

'But he's exiting so we're currently speaking to different partners and different ways of doing it moving forward.’

What of his own exit plan? ‘I said that when I was 50 I wanted to settle into being more laser-focused and have a more singular role,' Neville says. 'I’m probably four years behind. It needs to be something that's important.

'I don't think it can be politics now. I thought about it at a certain point. I'd get stuck in the mud and I can't get stuck in the mud.

'It would have to be something that's connected to sport, business, that in some way puts me into a position whereby I can put the experiences of the last 30, 40 years of football, media and business together and bring value to someone or something.’

An executive role at Manchester United? ‘I don't think it would be that, it’s unlikely to happen and not something that I would think that I would want to do.’

First things first. There is something else to prepare for – this Tuesday’s celebrations.

‘I've got a little day out planned,’ Neville says. ‘It involves a walk and a couple of activities. A group of about 25, 30 people.

'Phil can't get back from America but my sister (Melbourne Mavericks netball coach and legendary former England player Tracey) is home from Australia, which is amazing.

‘I'm proud of my brother and sister. Phil (currently manager of Portland Timbers) is sticking at it. They don't give in.’

It would appear to be a Neville family trait.