Manchester City coach Pep Guardiola has hit back after Gary Neville claimed young midfielder Phil Foden was at "the wrong Manchester club" to get first-team opportunities.
Foden, 17, produced a fine display as City lost to United in the International Champions Cup earlier this month, with Guardiola saying his performance had been on "another level."
But writing on Twitter, former United player Neville, now a TV pundit, said: "He's at the wrong Manchester club for getting a sustained opportunity. City have a lot of great kids. They should be playing."
Guardiola said good young players would get a chance at City despite the club's huge investment in the first-team squad.
He told reporters: "I'm not going to put young players in the squad because they are young. They will be in the squad because they have quality. I don't have problems with that.
"The club is working well in terms of the academy. There are many players with good prospects for the future. We will be patient with those guys. They are going to train with us most, or part of, the season.
"Phil Foden is going to play in the next games. He has the quality to play in that team. I'm so happy to have him. He's a Mancunian, a City fan, a humble guy. He's a fighter."