I didn't say he shouldn't be used, just that IMO is not at the level where he will play as a choice at LWB. It is better to have the squad as near to the 25 limit as possible and have players who can contribute through the season no matter how much that might be. As he is still young and with the best coaching set-up around he has the opportunity to develop for sure and I hope that happens
I don't believe Pep would specifically bring in a player he doesn't plan on using. He likes a small squad, he hates leaving people out and managing unhappy players - and players who don't play are always unhapppy.