Because Clyne and Walker are better than him, and are equally in good form.
How many can you take in the squad? 25?
Forgot about Walker but it all depends who they intend to have in front of them. I get the impression that not only on here but in general people expect they're defenders to be decent at attacking primarily these days, which is a load of shite imo, obviously depending on tactics, etc.
We could potentially playing with a diamond formation in the summer and for that to work you need your full backs to be able to attack and provide width.