Sir Alex Ferguson told Jose Mourinho to sign one player during his spell at Man United

Jose Mourinho once revealed that Sir Alex Ferguson told him to sign a player at Manchester United, hailing his mentality.

Mourinho managed Man United from May 2016 to December 2018 and received a piece of transfer advice from the legendary boss upon arriving at Old Trafford.

Ferguson, who retired from management in 2013, gave the Portuguese manager one advice in his two-and-a-half-years at the club.

Buy Dele Alli. Mourinho failed to acquire the player's services at Man United but managed the midfielder during his stint at Tottenham.

In a clip from Amazon's 'All or Nothing' series, the current AS Roma manager complains to chairman Daniel Levy about Alli.

"I told already Dele very directly that he doesn't train well, he is not a good trainer," he said.

"I am not saying a disaster, but I am not saying Harry Kane. Harry Kane is a very good trainer."

Dele Alli in action for Besiktas. Image: Alamy

Mourinho added: "Sir Alex Ferguson gave me only one bit of advice in two and a half years: Buy Dele Alli. 'That guy, with that mentality, the way he plays, the aggression he has in mind. This guy is the Manchester United player. Buy Dele Alli'.

"And he [Ferguson] has an eye for a player. But he [Alli] is not a good trainer, we need to find motivation for the guy."

Alli, who starred for MK Dons in their upset win over Man United in the EFL Cup back in 2014, signed for Spurs after impressing in League One.

He was a regular at Spurs in his first three seasons, then fell down the pecking order before enduring a big slump in his career.

He left Spurs to join Everton but failed to make a huge impact, then signed for Besiktas on loan, where he was unable to make an impression.

Will the 27-year-old resurrect his career? Let us know.