On a Sunday morning in September 2004, Mark Walsh was about to take charge of his City Colts under-9 side for a game on the outskirts of Milton Keynes when he felt a tug on his tracksuit sleeve.
He looked down to find an eight-year-old boy with bright eyes and a big smile, dressed in a football kit, desperately trying to get his attention.
"Excuse me, can I play too please?" asked the boy, who had come along to watch his friends in the game.
Walsh explained this was a formal league game and that you had to be registered with the club and the league to take part.
"I'm good at football, honest. I really am," the boy pleaded.
Walsh apologized and said it really wasn't possible, but he told him to come along to his team's training session the following week.
Sure enough, the next week the boy was there and ready to go.
"And as soon as he touched the ball and started playing," Walsh recalls, "I knew there and then that one day he would become a professional footballer."
The boy was Dele Alli, and what Walsh saw that day was one of the first signs of what would become a phenomenon in English football—a 22-year-old midfielder who is now widely recognized as the country's most naturally gifted player of his generation and has been estimated by the CIES Football Observatory as the second-most valuable footballer in the world, behind Brazilian superstar Neymar.
But what Walsh saw that day was also indicative of just how different Alli's story has been from most other prodigious talents.
It's not the story of a player who spent his childhood cosseted in the academy of one of the world's best clubs. It's the story of a player who's risen all the way to the top the hard way, playing in the harsh and unforgiving environment of English football's lower leagues.
Before he stumbled upon Mark Walsh and the City Colts, Alli had only played on the streets and inside small concrete cages around Milton Keynes in Buckinghamshire.
"Dele had grown up playing in these cages against bigger and older boys, which toughened him up, helped to perfect his skills, and I really think made him the player he is today," Walsh says.
Alli endured a difficult upbringing in the Bradwell area of the town, where he lived with a mother suffering from alcoholism, Denise, his half-brother and two half-sisters—but without his father, who returned to Nigeria only a week after Alli was born.
"Times were difficult, very tough," Denise told The Sun in 2016. "I had four children by four different dads, but none of the relationships lasted. I was a single mum. We were living in a council house, but it was a bit rough."
Football would prove to be Alli's salvation, and he could usually be found outside his house with a ball at this feet.
For two years, Alli played for City Colts and Mark Walsh, who would pick him up and drop him home from training each week. There he flourished and found a much-needed sense of belonging.
"He had such confidence on the ball, which is rare for players of that age," Walsh says. "He wanted to take risks. He wanted to express himself. He loved to play. Football was everything to him.
"But if things did not go his way, he could also sulk, and sometimes I had to sit him out of sessions. He could get emotional and always wanted things to go his way."
Walsh's favorite memory of managing Alli came in the summer of 2005, when City Colts played in the local Willen World Cup tournament, where each team is named after a different nation.
"In the first match, our opponents kicked off, Dele intercepted the ball, beat four players and scored. Our opponents kicked off again, and Dele did it all over again: beat four players and scored. We were 2-0 up, and the other team had touched the ball just twice.
"When they kicked off a third time, Dele won the ball again and then jumped on top of it and stayed there, balancing on it. The referee threatened to send him off for showboating. We managed to talk him out of it because this was Dele. He wasn't goading anyone. He was just trying different things and having fun."
In 2006, when Walsh got a job as a youth coach at Milton Keynes Dons, he took a 10-year-old Alli with him and, after a six-week trial, was able to offer him a place at the club's academy.
For the next two years, Walsh managed Alli for MK Dons' Under-11 and -12 sides before he progressed to the older teams under Dan Micciche, who has since worked for the Football Association before returning to manage the MK Dons first team.
The coaches were told to give him as much freedom as possible—not "overcoach" him but simply allow his game to develop naturally.
"He thrived on training four times a week. He just got better and better," Walsh says. "His name soon spread across the club, with the first-team manager, Karl Robinson, coming to watch him."
At the same time, Alli's home life had gained greater stability after, at the age of 13, he moved out of his mother's house and went to live six miles away with Alan and Sally Hickford, the parents of his friend Harry, who also played for City Colts and MK Dons.
"All the kids Dele's age were on the streets smoking, arguing and robbing. Some ended up in prison. I was worried my son would be tempted by that hood life," his mother told The Sun.
"The Hickfords weren't my friends, but they had a nice home and I knew I had to give my son this chance to move on with his life and succeed. When he left, there were no tears—just a sense of relief because I knew he would be off the streets and safe.'"
The Hickfords, described by Karl Robinson as "phenomenal people," have never formally adopted Alli, and neither they nor Alli have ever spoken about it. But after moving in with them, Alli continued to prosper as he made his way through the ranks at MK Dons.
When Alli was only 15 and still at school, MK Dons manager Robinson invited him and two other talented young players, Brendan Galloway and George Williams, to train with the first team.
The senior players had seen this all before—shy young players nervously joining in with them and playing safe five-yard passes. But they quickly learned Dele Alli was a bit different.
"Within minutes of training with us for the first time, Dele had nutmegged me," laughs former MK Dons midfielder Darren Potter, who is now at Rotherham.
"I couldn't believe it. I was speechless. He put the ball through my legs and ran around the other side. You don't do that, but he didn't care. When I was a young player, you wouldn't dare do that to an older player, but Dele was this silent assassin with a cheeky grin.
"'This kid is going to be a superstar' is what Karl Robinson kept telling me. I know him well, and he never wavered. He was adamant Dele Alli would be one of the best."
In November 2012, Robinson handed Alli his first-team debut at just 16 years old. He came on as a substitute against Cambridge City in the first round of the FA Cup.
"So Dele strolls onto the pitch, and his very first touch of the ball is a backheel!" recalls Potter. "You don't normally see that, but Dele was always different. We had almost come to expect it."
The game finished in a goalless draw, but in the replay, Alli would score with a brilliant 30-yard shot in a 6-1 win. "We all sat up at that goal and thought, 'Oh wow,'" Potter says.
"I soon came to see [Alli] shared the same qualities of some of the players I played with at United," Chadwick says. "Because he had this overwhelming belief in himself. Nothing scared him."
Still, Robinson was slow to integrate Alli into the first team; the youngster played just five more games in the rest of the 2012-13 season.
David Martin was at MK Dons for 13 years, making 289 appearances for the club before moving to Millwall last summer, and was Alli's roommate on his first away trips with the first team.
"They thought I was a sensible guy to room with, as I was a few years older," laughs Martin. "Normally kids are full of nerves at that age, but what surprised me was he was the complete opposite.
"He opened up and talked about his home life, and what struck me was how completely switched on he was, how he knew what was going on and let nothing get on top of him. He just had it."
Martin wasn't the only one to see it. Alli earned the respect of the full first-team squad during his preseason training in the summer of 2013.
"He turned up and ran everyone into the ground," Martin says. "He was just a 17-year-old kid and blew everyone away with his fitness in his first real preseason. He was an absolute machine.
"We have a drill called the flower run where you run from the 18-yard box to the centre circle and to various points of the pitch, and from above it looks like a flower. You have to do it in sprints—and in a certain time—and it can be brutal.
"I will never forget the sight of Dele running past players, just breezing past them, and laughing. Experienced players were in pain, struggling their way around, and it was nothing to him."
In the 2013-14 season, despite being only 17 years old, Alli became a first-team regular, playing in midfield alongside the experienced Potter, who was 12 years his senior.
"Karl said to me, 'It is you and Dele now,' and I did wonder if he was ready," Potter says. "But he was so consistent. He made it easy for me to play as a defensive midfielder, because Dele played in front of me and has an incredible engine. I just sat back and admired him.
In his first full season, Alli became a vital part of the MK Dons side, playing 37 games and scoring seven goals in all competitions, including a hat-trick against Notts County.
"The truth is the team came to rely on him," Martin says. "He was everywhere and a dream to play alongside. With Dele on the pitch, we always had a chance to win games. Everything went through the middle because of him. I lost count of the number of times I texted him after games to say, 'That was different class, mate.'"
By the start of the 2014-15 season, word had naturally spread about Alli, and when Manchester United visited for the second round of the League Cup at the end of August, the stands at Stadium MK were heaving with scouts and managers.
Tottenham Hotspur manager Mauricio Pochettino was there that night and only needed five minutes to make up his mind about Alli. It didn't hurt that the young midfielder helped MK Dons to a famous 4-0 win over United.
"Pochettino was in our boardroom after that game, and you could tell he was impressed at how Dele completely bossed the game," recalls MK Dons chairman Pete Winkelman. "That night, they knew they had seen the future in Dele Alli."
Tottenham would continue to monitor him—Robinson recalls how their scout and former manager, David Pleat, almost took up residence in his office before games—while there was also strong interest from both Aston Villa and Liverpool.
In the autumn of 2014, it became increasingly obvious to Alli's MK Dons teammates that he was outgrowing League One.
"He was getting too good for this level," Martin says. "He needed players to give him the ball quicker and players to move better around him. You could see he was ready for another challenge."
"It was just getting too easy for him. He had mastered football at the level and needed to move on," Potter agrees.
In January 2015, as Liverpool dithered, uncertain of Alli's ability to play in their first team, Tottenham bid £5 million and agreed to loan him back to MK Dons until the end of the season.
"During the negotiations with Spurs, I said to Dele, 'How about coming back until the end of the season?' and he just said, 'No problem, chairman. I'll do that,'" Winkelman recalls.
"This says all you need to know about Dele. This was his big move to the Premier League, but he agreed to stay with us for five more months. I've had players say the same thing, but in the cold light of day, they have their heads turned and leave immediately. But Dele is different and a wonderful character who stuck by his word."
MK Dons went on to gain promotion to the Championship as runners-up to Bristol City, with Alli contributing a decisive 16 league goals to be their second-highest scorer and claim the EFL Young Player of the Year award.
"We were grateful to get him back as he was our main man," Martin says. "When he came back after signing for Spurs, he was no different. Not at all arrogant. He is just a really nice lad. He buckled down and got us promoted."
At the end of that season, Alli's MK Dons teammates and manager waved him off to Tottenham, certain he would be a success. But all felt it would take time and have been surprised at the impact he has made in north London.
"I'll be honest, I knew he would do very well, but I thought he would go to Spurs and we would not hear from him for a while," Chadwick says. "He would need time to bed in. But he's gone there and become a star from the very start."
"I remember watching him on television in a preseason friendly against Real Madrid, and there he was nutmegging Luka Modric early in the game, just like he had done to me in that first training session!" Potter says.
Alli also earned a call-up to the England squad after only three starts in the Premier League, making his debut as a substitute against Estonia in October 2015. In the following month, he scored on his first start for England, against France at Wembley.
Then-England manager Roy Hodgson had been alerted to Alli's promise when he was still in League One. His assistant, Ray Lewington, had tipped him off, having been to regularly watch his son, Dean, play alongside Alli for MK Dons.
Alli's career has been marked by a seamless, almost effortless rise through each challenge he has been presented with.
He had hoped to make 10 starts for Tottenham in his first season. Instead, he made 33 and has since emerged as one of the catalysts for the club's success under Pochettino over the past three seasons.
It took Alli just 52 games to score 20 Premier League goals. In comparison, Paul Scholes took 74 games, while Frank Lampard and Steven Gerrard didn't reach the same total until they had played 140 and 169 games, respectively.
"Dele's success is down to the grounding he got in the game, playing real games for MK Dons, rather than being hidden in youth teams," Chadwick says. "There is no substitute for actually playing, and he left for Tottenham with close to 100 games under his belt."
"Dele is the player he is today because he played in the gladiatorial and combative world of League One from an early age," his former chairman, Winkelman, says.
One day after the fifth anniversary of Alli's debut for MK Dons at non-league Cambridge, which came in front of a crowd of 500, he scored twice for Tottenham in a 3-1 win against reigning European champions Real Madrid in the Champions League at Wembley. In 102 appearances in the Premier League, he has amassed a total of 36 goals and 26 assists.
"This is only the start for him," Chadwick says. "He will soon become one of the top 10 players in the world and should be England's most important player at the World Cup."
Mark Walsh doesn't have much contact with Alli these days, but he did receive a signed Tottenham shirt from him, which he had framed and proudly placed on his wall at home.
Walsh is actually a Tottenham fan, having grown up watching Glenn Hoddle and Chris Waddle from the stands. He finds it surreal to watch Alli wearing the same shirt and striding around White Hart Lane or Wembley.
"Whenever I see him play and the fans sing his name," Walsh says, "I can't help but think about the eight-year-old I met all those years ago who wanted to play in our game.
"He has come a long, long way."