In February 2015, Tottenham Hotspur brought Dele Alli to north London for £5 million, sending the 18-year-old straight back to MK Dons on loan. For a teenager playing League One football, it was a considerable investment — one that, in the short term, looked inspired.

Alli wrapped up his final season at MK Dons with 16 goals in 39 league matches before making the jump to the Premier League. The transition could not have gone more smoothly. He scored 10 goals and provided nine assists in his debut Spurs campaign, then followed that up with 18 goals and seven assists in his second season. Back-to-back PFA Young Player of the Year awards underlined just how far he had come.

A force in Pochettino's Spurs

At White Hart Lane, chants of 'We've got Alli! Dele Alli!' rang out regularly. He formed a devastating attacking unit alongside Harry Kane, Son Heung-min, and Christian Eriksen under Mauricio Pochettino's 4-2-3-1 system, and his performances even caught the eye of Real Madrid.

Nine goals and 10 assists in the 2017/18 season suggested the good times would continue. But the 2018/19 campaign brought a run of hamstring injuries that disrupted his rhythm and blunted his effectiveness. The decline had begun.

Mourinho's warning and a worsening situation

When Pochettino departed in November 2019, Dele lost his most important ally at the club. Incoming manager Jose Mourinho was blunt in his assessment, cautioning the midfielder that unprofessionalism would derail his career. A widely viewed scene from the Amazon documentary All or Nothing showed Alli sitting across from Mourinho, arms crossed, visibly unreceptive to his manager's counsel.