I doubt Navas is good enough for what Pep is looking for in a right back.
BUT [and it's a big BUT], Navas has done a fantastic job vs Arsenal and Chelsea i.e. Sanchez and Hazard. Without forgetting going foreword whenever possible. For someone who has never played right back before and has hardly played any games before he was put in vs Arsenal, that to me is some achievement.
It typifies Navas the player. Great professional, great squad player, always gives his all, but not good enough for where we wanna be to claim a regular starting place. As a squad player I would have no problems him staying around, but for the player himself it's better to move on or back to Sevilla. If he does I will look back at how he performed and state he has been worth the transferkitty.