Since joining Tottenham Hotspur in 2015, Alli has played in a Champions League final, World Cup semi-final and racked up a whole host of individual honours.
At just 25 years old, he has played well over 300 professional games and amassed 37 caps for England. With his best years still ahead of him, Planet Sport celebrates Dele Alli's most iconic moments.
Breaking through with MK Dons
Alli first featured in a Dons matchday squad in 2011, although it was the 2013/14 season when he properly caught the eye.
As a 17-year-old, the attacking midfielder became a key starter for Karl Robinson's team, making 33 appearances while registering nine goals/assists and winning the club's Young Player of the Year award.
Clubs higher up the divisions began to take notice, but Alli ended up staying at MK Dons for another season, one which proved to be his best so far.
MK Dons won promotion to the Championship for the first time in their history, with Alli an integral part of a free-flowing attacking team that included the likes of Lewis Baker, Benik Afobe and Will Grigg.
The highlight of the season, and maybe in MK Dons' history, came in the 4-0 League Cup victory over Manchester United that reportedly saw scouts from Liverpool and Bayern Munich in attendance to watch Alli first-hand.
The awards rolled in at the end of the season, with Alli sweeping up Football League Young Player of the Year, MK Dons Player's Player of the Year and a place in the PFA League One Team of the Year.
Signing for Tottenham Hotspur
Alli put pen to paper for Spurs in February 2015, before the London club loaned him back to MK Dons for the remainder of the season.
A debut season in the Premier League yielded 46 appearances and more than 20 combined goals and assists, leading to his first England cap just two months into his Spurs career.
The £5million signing shone in high-profile games, including the north London derby against Arsenal where a man-of-the-match display was followed by a new long-term contract just days later.
Like in his previous seasons, Alli collected numerous end-of-season awards. This time, he added the PFA Young Player of the Year and PFA Team of the Year to his honours list.
Despite attempts by Nigeria to convince Alli to declare for them, he made his debut for England, coming on as a substitute in a 2-0 win over Estonia.
A month later, Alli made his first start for the Three Lions against France and scored from distance to open his account on the international stage.
In March 2016, in a Euros warm-up against Germany in Berlin, England came from two goals down to win 3-2. Alli consequently won the BBC's man-of-the-match award for his influential performance in overturning the deficit.
That goal against Crystal Palace
It's up there with some of the best goals in Premier League history. Alli received the ball on the edge of the box, took a touch, flicked it up and over an onrushing Palace defender and proceeded to effortlessly volley home into the bottom corner.
It was a piece of breathtaking brilliance and is arguably Alli's most eyecatching individual moment.
The solo effort was enough to secure Alli the BBC Goal of the Season award at the conclusion of the 2015/16 campaign.
An even better 2016/17
After announcing himself in the Premier League the previous season, expectations were high in 2016/17. Yet Alli still managed to exceed them.
Alli is still yet to come close to replicating the kind of form he produced in his second season at Spurs. In 50 appearances, he recorded 22 goals and 13 assists.
Alli became a victim of his own success the following campaign, with fans and pundits expecting him to kick on to even bigger and better things.
Alli produced 15 goals and 17 assists, but still faced criticism from the media for the inconsistent nature of his performances. It proved to be the start of a rough patch for Alli and he is yet to rediscover his prolific goalscoring touch for Spurs.
2018 World Cup
He scored the second goal of the quarter-final win over Sweden and won the free-kick scored by Kieran Trippier in the semi-final against Croatia.
Next up on the international stage for Alli was the Nations League finals. England bowed out in the semi-final against the Netherlands and Alli was limited to a brief appearance.
His midfield partner at the World Cup, Lingard, found himself in an almost identical situation. And Alli can take heart from Lingard's renaissance following his recent move to West Ham, with the 28-year-old now almost certain to be part of Gareth Southgate's squad for this summer's Euros.
Champions League final
2018/19 passed without much note for Alli on an individual level. He captained Spurs against Watford in the Carabao Cup in a game played at his former hunting ground, Stadium MK.
Alli scored two penalties, one in normal time as well as the decider in the shootout, progressing his Spurs side to the fourth round.
Alli's season culminated with a place in Spurs' starting XI for the Champions League final against Liverpool, but after a largely anonymous 81 minutes, he was substituted for Fernando Llorente and Liverpool ran out 2-0 winners.
Alli and Mourinho never saw eye to eye throughout his tenure and, as a result, the England international spent 18 months on the periphery of the Spurs starting XI.
However, with Mourinho Roma-bound, there will be a new manager for Alli to impress and the chance to deliver on the promise he should in his early years at Spurs.