Don't think he'll ever be a starter at RB. He's done reasonably well there, but to play regularly, especially when the competitions heats up would be very difficult for him as he lacks some important attributes like pace and the defensive positioning which the best players would exploit rather easily.
If he was fast, then he could have used that until he got better, but lacking that too, it would be difficult for him. As a short-term option he'd be decent, but can't see him being our long-term RB.
Unless Lucho finds some love for Vidal again, and the latter keep improving defensively, he could fill that role, or else we'd have to sign someone.