Defenders
Right so he's got all the basics to become a top defender. What's the problem?
He's still got another 5 years learning the game before he reaches his peak.
10 before he should reach his peak tbh
Not sure about that one mind...
At 31 he'll have the experience and should be reading the game much better than he does now. However, after 11 seasons in the physically hardest league in the world, his legs will probably have gone. Any pace he may have had to get him out of trouble will have gone too. It's not his fault but (potentially) 400 games down the line - he'll be on the way down, sadly.
Defenders peak late 20s to early 30s tbh.
He has many attributes which could lead to him becoming a solid center-back for NUFC. If you look at his rivals in the u21's: Anton Ferdinand, Liam Ridgewell etc they all are error prone as each other. Experience will boost his decision making and good training could mould him into a good defender.