Paul Pogba says he plans to stay and help Manchester United teammate to develop his game.
Pogba has described Greenwood as the "best finisher" he has ever seen.
The United youngster took his tally of goals for the season to three on Sunday, netting the winner in the 1-0 win over Wolverhampton Wanderers.
Pogba told Stadium Astro: "Mason I think he's more left footed, he dribbles more with his left but to shoot he shoots with both. His finishing is unreal, he's the best finisher I've seen, trained with. He's the youngest but he's just unbelievable and I hope he score more goals and improve and win titles.
"He's very young and very talented and I want to push him even better."