I'm willing to hold him for a few weeks in redraft to see how it all shakes out.
At this point- why wouldn't you hold him?
If he is on your roster, you were already gambling that he could grab a bigger share of the backfield. Now, it looks like it has fallen into his lap - so, the thing you were gambling on - has happened.
The better question - should you trade him? You either drafted him very late, or picked up in waivers - so it's unlikely you were expecting him to be a consistent starter for your team. So, as an extra piece, can you trade him for someone to improve your squad? The answer depends on your squad and your league - but I suspect, the best move here is to trade him now.