Erik Ten Hag believes playing with Casemiro will help Kobbie Mainoo reach his potential more quickly.
Eighteen-year-old Mainoo has been the brightest part of a difficult season so far for Manchester United, with the midfielder establishing himself as an important member of the side.
The teenager was given his chance following the hamstring injury suffered by Casemiro at the beginning of November.
But the Brazil international, who is 13 years Mainoo’s senior, is now fit again and they have played together in the last three games, all of which United have won.
Boss Ten Hag said: “We missed over a long period very important players like Casemiro, (Lisandro) Martinez, Luke Shaw, also others. We discussed that often. But you see the impact from a player when he is there, like Casemiro.
“He gives you calmness and composure on the ball. He gives you options, he does see the vertical pass.
“He is always a step ahead of his opponent and can break lines. Casemiro is a very important player for our game. We are happy he is back.
“For Kobbie Mainoo, he can learn a lot from it. That togetherness, that bond, also Kobbie is very coachable and Casemiro has so much experience.
“Kobbie will learn a lot from it, and that can even accelerate his development. We are happy to have him and, when they play together, they can benefit from each other.
“Casa takes that responsibility. He has taken to him and he is talking to him.
“I see it in the dressing room and on the pitch, also in training and in games. He is looking at his own game, but he is trying to help and support Kobbie Mainoo.”
Green shoots have emerged among a troubled time at Old Trafford in the form of Mainoo and his fellow young guns Rasmus Hojlund and Alejandro Garnacho.
All have been to the fore in United’s improved form, which sees them head into Sunday’s clash with Aston Villa chasing a fourth successive win.
Ten Hag is mindful, though, of not overplaying his rising stars, saying: “I brought them out on Sunday because it was the second game in nearly three days.
“I brought them out against Nottingham Forest, the third game in a week, and I have to protect the player.
“They have to get used to the Premier League’s intensity. You can only train this in the Premier League or Champions League where you have to perform every third day.
“Then you have to make considerations about the team and result, but also about protecting players so they don’t get injured.
“Kobbie was twice injured and we don’t want to come into that situation again because it halts his progress.”