For footballers at the top of the professional game, the early weeks of a new season are a time of giddy excitement.

For some, the summer may have brought a dream move to a big club, or the expectation of one imminently as the final days of the transfer window loom. For others, promotion might have brought greater financial rewards and the chance to challenge for some of the game's biggest prizes.

These are the dreams young footballers nurture, but the reality - for the majority of professional footballers - is very different.

The Professional Footballers' Association (PFA) estimates that each summer, about 700 players are released by their clubs, causing upset and uncertainty.

"The biggest attrition rate is undoubtedly among young players," says Oshor Williams of the PFA's education department, which offers support and training to prepare them for a life outside professional football.

"Of those entering the game aged 16, two years down the line, 50% will be outside professional football. If we look at the same cohort at 21, the attrition rate is 75% or above.

"Most of these kids don't have a Plan B. It can be very unnerving to find yourself having to move into a completely different world."

So what happens to those who slip through the net? BBC Sport spoke to four men released by some of the country's leading clubs and whose lives took very different paths - into prison, gambling, medicine and the lower leagues.

'I've made every mistake in the book'

Midfielder Josh Payne broke into the West Ham first-team squad in 2009 aged 18, making two appearances in the Premier League. He was released a year later and went on to serve a six-month prison sentence for actual bodily harm and assault. He now plays part-time for Woking FC.

Payne now plays part-time for Woking after failing to make the grade at West Ham

Payne was one of those young players for whom everything seemed to be going right. A star of the West Ham academy, he captained the club's vaunted under-18 side and earned his professional contract a year early. He broke into Gianfranco Zola's first-team squad, making his Premier League debut in March 2009 against Blackburn Rovers.

A newspaper report at the time described Payne as "a young man in a hurry... destined for big things".

"It was very exciting," Payne remembers."I was training with the likes of Scott Parker, Alessandro Diamanti, Diego Tristan. It was brilliant to be involved."

And then, suddenly, everything started to go wrong."I took my foot off the pedal," Payne says."That was my biggest downfall - I had a bit of success and I thought 'I've arrived here'. It comes all at once and you don't know what to do. I thought I could relax."

Payne was called into the manager's office and told he would not be offered a new contract."It was only when somebody sat me down and those words came out of their mouth that I realised I hadn't kicked on," he says."It hit me - I didn't want it enough. I didn't realise how good I had it."

The cultured midfielder signed a six-month deal at Doncaster Rovers, but struggled to establish himself. Spells followed at Oxford United, then Aldershot Town. That was where his troubles deepened.

"People make mistakes every single minute of every day," Payne says reflectively."I just made one a bit bigger than everyone else."

Payne got into a fight outside a Guildford nightclub. In an act of drunken stupidity, he punched a man and hit him with his belt.

"I knew I'd done wrong," says Payne."I wasn't a man when I committed the crime - I thought I was, but I wasn't."

Payne received a 12-month prison sentence for ABH and assault."I remember being led away," he says."I'd packed a bag but I hadn't even got the right clothes. I was stripped of everything. I'll never forget the first night."

He spent six months at HM Prison High Down in Surrey. During that time, he missed his daughter's first birthday and Christmas."It was a nightmare," he says.

Payne emerged from jail determined to get his life back on track. He signed part-time at Conference club Woking. Last season, he won the club's Player of the Season award and earned a call-up for England C, representing his country at non-league level.

"I'm a lot stronger and wiser now," he says."I appreciate football a million times more - being free to express myself on the pitch, free to work hard and enjoy working hard."

Payne believes young footballers should be offered greater emotional support by their clubs.

"I'd love so much for clubs to have people to talk to the young players," he says."I wish I'd had somebody. I've made every mistake in the book. Of course I have regrets - I let a massive opportunity slip away."

'I was gambling £20,000 in a single bet'

Midfielder Gavin Heeroo was a trainee on the books of Crystal Palace. After being released in 2004, he developed a gambling addiction. He conquered his betting habit with the help of the Sporting Chance clinic and now runs his own business.

Heeroo dreamed of making it at Crystal Palace but ended up launching his own fitness business

Heeroo left school at 16 and signed for Crystal Palace as a trainee. Among his team-mates in the Eagles youth team were Wayne Routledge, now at Swansea, and Ben Watson, who scored the winner in the 2013 FA Cup final for Wigan against Manchester City. Heeroo's career was not destined to have such a fairytale ending.

"I loved every minute of it," says Heeroo, who grew up on the notoriously tough Broadwater Farm estate in Tottenham, north London."I did train hard, but I wasn't as focused as I could have been. Being a London boy didn't help - you have all the temptations on your doorstep. I got caught up in the lifestyle."

Heeroo says he was relieved when he was let go by the club after two years.

"Iain Dowie called me into his office and told me I needed to go and play football," Heeroo remembers."I wasn't devastated at all - I felt like a weight had been lifted. Iain was great but the club didn't give me any support."

Heeroo had offers from League clubs, but joined then-Conference National side Grays Athletic in an effort to hang on to his flashy lifestyle.

"I always saw professional football as a job, like any other industry," he explains."Sometimes you can get paid more at a lower level than you can in the higher divisions. It might not be a great move for your career, but you need the income. I had a flat and a car. I was still hooked on the lifestyle."

In hindsight, Heeroo admits, dropping out of the Football League was a mistake.

"I dropped too low," he says."When you're in the lower leagues it's hard to get noticed; it's hard to get out. It's very difficult. You have been so pampered and then suddenly you have to clean your own kit."

Missing the excitement and glamour of top-level football, Heeroo turned to gambling.

"It's not so much the money that you're hooked on as the buzz," he explains."I was trying to replicate the adrenalin rush. At one stage I was gambling £10,000 or £20,000 in a single bet. I was betting more than I could afford to lose. It's a scary place to be."

Heeroo conquered his addiction with the help of Sporting Chance, the clinic founded by former Arsenal captain - and one-time alcoholic - Tony Adams.

With his football career waning, Heeroo decided to start his own fitness business with friend and former Palace team-mate Dougie Freedman, the current Bolton boss who also managed the Eagles.

"I did a fitness course," he says."I'd always enjoyed keeping myself fit and I found that I really loved helping other people to achieve their goals."

Now Heeroo is using his company, Focus Fitness, to rescue other young footballers, by hiring ex-players to run personal-training sessions.

"I think there's a lack of support [for young players]," he says."Organisations need to be more accountable. I always strongly believed that if football didn't work out, I could do anything I put my mind to. Other kids might not be so lucky."

'Realising I could be a doctor was inspirational'

Striker Michael Hazeldine joined Wigan Athletic aged 13. He became a reserve-team regular for the Latics and played one first-team game before being released in 2006 aged 19. He went on to study medicine at Edinburgh University and is now training to be a GP.

"I think I always dreamed of being a professional footballer," he says."I felt I was good enough and I had the opportunity, so I thought that was the way I was going to go."

Hazeldine was a promising junior footballer at Wigan Athletic between the ages of 13 and 19

Snapped up by Wigan as a precociously talented 13-year-old, Hazeldine went on to earn a three-year trainee scholarship at the age of 16. By 18, he was playing regularly for the reserves and training with the first team.

"It was a big step," Hazeldine remembers."Just mixing with the players, around the training ground or in the canteen, seeing these big names - Jimmy Bullard, Jason Roberts - they were very exciting times for a young player. It felt like we'd got to the last step and things were within touching distance."

But like many young players, Hazeldine found the last step the most difficult. When his youth contract ended, he and his fellow scholars were summoned to the manager's office to receive the dreaded news - none of them would be offered a professional deal.

"Paul Jewell called me in and said: 'Your dedication is second to none, but you're not ready to go into our first team,'" Hazeldine remembers."The other lads were devastated because all their eggs were in that basket."

But unlike most of his peers, Hazeldine had prepared for the possibility that he might not be kept on. Wigan had offered him the opportunity to attend college once a week to pursue A-levels - a chance he grabbed with both hands.

"I was always aware of the need to have a back-up plan," he says."You see the number of players who are released, so you know the chances. I spent most of my free time studying from the age of 15 to 19. That's what you need to do - although football's a fantastic way to go, a lot of players don't make it."

Hazeldine's hard work paid off when he achieved three As at A-level. He decided to apply to university to study medicine and won a place at Edinburgh.

"I'd always viewed being a doctor as one of the most rewarding careers, and realising that I had the ability to do that was an inspiration," he says.

Hazeldine, who credits the PFA for its guidance as he negotiated the transition from football to university, is currently working in a paediatric accident and emergency ward as part of his training towards becoming a GP.

"Doing the job I'm doing now, I'm able to make children better when they come in sick," he says."I'm finding it hugely rewarding."

But Hazeldine is aware that his happy ending is an unusual outcome for a released footballer.

Hazeldine is working on an A&E ward as he trains to become a GP

"I don't think there's a fallback for a lot of players," he says."Suddenly your contract ends and you're in the wilderness.

"You're aware that you might not make it, but you think you will. Then that reality comes home and you realise: 'That road's closed, got to look elsewhere.'"

'I had to face the fact I wasn't good enough'

Midfielder Tom Taiwo was rated one of the most exciting prospects in the English game when he signed for Chelsea in 2006 aged 16, but he suffered a serious injury and never played a first-team game. He stayed in professional football and is currently at Falkirk.

Taiwo is now at Falkirk (left) following previous stints with Hibs and Carlisle after leaving Chelsea

Taiwo was still in school, aged 16, when he was spotted by Chelsea while playing for England Under-16s and subsequently poached from Leeds United's academy for a seven-figure fee in a transfer saga that made national headlines.

He was living every schoolboy's dream."When a club like Chelsea wants you, you have the dream of playing in front of 45,000 people each week and competing for trophies," he explains."You have that real excitement. You feel you can tackle anything."

But that adolescent aura of invincibility soon faded. A stellar cast of midfielders kept him languishing on the sidelines and then, two days before he was due to make his debut for the youth team, he suffered a broken leg.

"I always felt like I was playing catch-up," Taiwo says."The club had a glut of players in my position and I was unlucky enough to suffer a serious injury. There's always somebody younger than you coming through."

With his first-team prospects receding, Taiwo went out on loan to Carlisle United. After six months, he was told that he was not wanted at Chelsea and that his move to Brunton Park would be permanent.

"I was disappointed," he remembers."But I also have to look back and say I wasn't good enough. That can be quite a painful thing to say. As a young footballer, you can be quite blinded at times. It was the first time in my life I'd ever suffered a real setback. I had to face the fact that I wasn't as good as I hoped I'd be."

At that crossroads, many players would have considered giving up. But Taiwo credits the advice of Chelsea youth-team coach Neil Bath for persuading him to continue his football career.

"It was a very difficult situation," Taiwo says."But football was my passion, and still is. It's a sport that grips you and offers you an amazing lifestyle. It's a great feeling to wake up every morning and know you're going to do a job that you really love."

Taiwo became a regular at Carlisle, winning the Johnstone's Paint Trophy at Wembley in 2011. He then spent two successful seasons north of the border at Hibernian and now plays for Scottish Championship club Falkirk.

He has not fulfilled all his dreams but Taiwo, now 24, says: "Looking back on my career now, it's not turned out the way I hoped when I was 16.

"I wanted to be an England international and a regular at Chelsea, all the things that everybody dreams of as a kid. But I've got no regrets.

"If I make it to the Premier League in two years' time, then I'll know that I really deserved it. If not, then I'll know I've put in all the hard graft and it's just not meant to be."