Rio Ferdinand has backed France midfielder Paul Pogba to become the best midfielder in the world.
Pogba has caught the eye with some outstanding displays as Didier Deschamps' side have moved into the quarter-finals of the FIFA World Cup in Brazil.
France were not talked up as potential challengers to be crowned world champions for a second time, but have emerged as serious contenders as they prepare to lock horns with Germany in the last eight on Friday.
Pogba's influence has not been lost on Ferdinand, who has not been surprised by the impact the Juventus man has made on the world stage after seeing him at close quarters during his time at Manchester United before the 21-year-old opted to join the Serie A champions.
The former England defender said in his column on the BBC Sport website: "Young France midfielder Paul Pogba has been one of the stars of this World Cup but I am not surprised by his impressive form in Brazil.
"Pogba did not play much during his time as a team-mate of mine at Old Trafford, but the things he did in training meant every member of Manchester United's first-team squad was in no doubt how good he was, and how good he could be.
"It was a big disappointment when he left to join Juventus in 2012, and it was definitely a mistake by United to let him go.
"I think he left because he felt disrespected that he did not play in a particular game when a few players were played out of position in midfield.
"Paul told me before he left that he wanted to be "the best player in the world". I don't know whether that will happen, but he will definitely turn out to be the best midfielder in the world.
"As well as his undoubted ability, his strength is definitely his self-belief, not just by statements like that but by how he backs them up.
"He made the big bold move to leave United, the best club in the world in my eyes, at only 19 because he wanted opportunities. He backed himself to do it, which is a big thing to do for a kid of his age, and he has not looked back since."