It's going to be hard for him because he doesn't seem to have the flexibility to play as a full back for example. That would help him at least secure a regular squad position, maybe a few sub appearances even a start or two. Today he looks lightweight and too much of a risk to occupy such a crucial position in the teams spine.
He didn't stand out for me in the U21, neither did he stink the place out. What he needs is a few years playing in Spain or Portugal, regularly, then come back to the prem when he is strong enough to handle it. That's what Chelsea did with Matic.