Harry Maguire described Kobbie Mainoo as "a real monster" in midfield and said his improvement at Manchester United was down to the coaching of Michael Carrick and his staff.
Mainoo was ostracised under Ruben Amorim and could have left the club on loan last January if the Portuguese head coach hadn't been sacked at the end of that month following a falling-out with director of football Jason Wilcox.
Return to the fold under Carrick
Until Carrick was appointed, Mainoo hadn't started a Premier League game all season, but he returned to the fold under the former United midfielder and was one of the club's best players in the second half of last season.
The academy graduate formed a strong partnership with Casemiro in Carrick's 4-2-3-1 system, but with the Brazilian leaving the club at the end of last season, Mainoo played the deeper role in midfield against Ipswich on Sunday.
That was his first start since the end of last season, having endured a difficult World Cup in which he didn't play a single minute, but he hit the ground running and delivered another superb all-action midfield display in the 5-2 win.
Maguire praises off-the-ball work
His improvement off the ball under Carrick has been particularly noticeable and centre-back Maguire said it was clear the 21-year-old had taken a step forward over the last eight months.
"I thought he was brilliant," said Maguire after Sunday's win. "I think to say he hasn't played for I don't know how long, not really got many minutes in pre-season and things like that, he was magnificent."
"He put a great shift in and I think his work without the ball has improved so much since Michael's been in. That's probably credit to Michael and his staff."
"I think without the ball now he's becoming a real monster in there, and I think he wins a lot of second balls. He wins a lot of duels. You won't want to play against him in there and that's the biggest compliment I can give to him from playing and watching him behind."
Difficult spells overcome
Amorim played Mainoo as a more attacking midfielder and once even fielded him as a striker, as he harboured doubts about his work off the ball and his defensive contribution.
The midfielder shrugged off that difficult spell when Carrick came in, and he looks to have done the same after the World Cup, when Thomas Tuchel ignored his claims and played Reece James and Jordan Henderson in midfield ahead of him.
"He's so young, if we want him to play for this club for another 10 years, I think there's going to be times where he's going to go through a patch like with Rashy and myself, but that's part and parcel," said Maguire.
"I think he's really level-headed, he's really composed, he has great belief in his ability and he's going to be a magnificent player for this club for many, many years."
