Casemiro believes Kobbie Mainoo is "the present" at Manchester United, but insisted the youngster must fear losing his place to become better.

After struggling for minutes under Ruben Amorim earlier in the season, Mainoo has become a key player under interim head coach Michael Carrick.

Mainoo has played the second-most minutes for United under Carrick, while the midfielder has completed the most passes (698), registered the third-most interceptions (16) and won the third-most tackles (15).

The 21-year-old recently signed a new five-year deal at the club, keeping him at Old Trafford until June 2031.

Mainoo's form has helped United secure a return to the Champions League next season, while Carrick has been linked with a permanent role at the club.

Casemiro, however, has urged Mainoo to stay focused in training and not forget his struggles earlier in the season.

"He's very easy. He's slow. He's a calm guy. Very calm. But for me this guy is the present in the football club," Casemiro said on the Rio Ferdinand Presents YouTube channel.

"Kobbie is an unbelievable player but he needs to train, train, train.

"He needs fear: ‘I play, I don’t play.' In this moment [under Amorim] he doesn’t play too much and I talked to him: maybe it’s the first time he doesn’t play, but it’s not the last.

"You don’t need to drop the training. You don’t need to drop your head. You need change. How? Work. Work. Work. Talk with the manager what you need to change about this."

United need just one more point from their final two games to secure a third-place finish in the Premier League.

The Red Devils host Nottingham Forest on Sunday before closing out their season against Brighton on May 24.