Jose Mourinho has revealed the only advice Sir Alex Ferguson gave him when manager of Manchester United was to sign Dele Alli.
Mourinho, who now manages Alli at Tottenham, made the confession to his chairman Daniel Levy in a meeting shown on the Amazon Prime Video documentary All or Nothing.
The Portuguese had just taken over from Mauricio Pochettino in north London and was discussing his early impressions of Alli.
He said: "I told already Dele very directly that he doesn't train well, he is not a good trainer.
"I am not saying a disaster but I am not saying Harry Kane, Harry Kane is a very good trainer.
"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 was one of the brightest prospects in the game after bursting on to the scene at Spurs following his move from MK Dons, scoring 18 goals in the 2016/17 Premier League season.
However, injuries have seen him limited to just 25 league appearances in each of the past two seasons, with his goal tally and influence also decreasing.
Mourinho was shown to be forthcoming with his views on Alli in the documentary, often calling the attacker out for his limp efforts in training.
During Mourinho's first training session, he accused Alli of being "lazy", before saying: "I am going to be a pain in the ass for you. And you are lucky because when I am a pain in the ass it means I like you."
Mourinho was more constructive in a one-on-one meeting with his player in his office but questioned whether Alli's "party boy" lifestyle could have contributed to his drop in form.
Spurs are set to begin the 2020/21 Premier League season against Everton on Saturday, September 12, with Mourinho looking to build on a sixth-placed finish to his first campaign in charge.