Man Utd signed Jadon Sancho despite Pep Guardiola's warning in 2019

Sancho had come through the Manchester City youth system under Guardiola in 2017, though he never made a senior appearance for the club.

Instead, he was sold to Borussia Dortmund for around 8 million pounds, where he quickly developed into one of Europe's most exciting attacking prospects.

Between 2017 and 2021, Sancho registered 50 goals and 64 assists in 137 appearances for the Bundesliga side.

Guardiola admitted he was pleased to see the youngster thrive in Germany but also noted Sancho's reluctance to compete for his position, a trait that may have sparked doubts about his adaptability.

"He didn't want to take this challenge [to fight his way into the first team], this opportunity to discover if he was able to," said Guardiola, when asked about Sancho's sale in 2019.

"He decided to go there. So, it's perfect. It's going well and congratulations on what he is doing.

"He is doing an incredible performance. He did it incredibly well this season. What would have happened this season [at City]? I don't know. Again, with the players, it depends on them and what they do on the pitch."

United, however, were undeterred. After years of chasing Sancho, they finally brought him to Old Trafford. His impact, though, fell well short of expectations.

Across his first two Premier League campaigns, Sancho managed just nine goals in 55 appearances, struggling to replicate the form that made him a star in Dortmund.

Sancho has since joined Aston Villa on loan from United.