Lots of other MLB teams bring up prospects and have them be on the bench, playing 2-3 times a week to give older guys a rest. I see no reason not to do that with Dozier, if he's ready. Service time is irrelevant to a guy his age, with his upside. We aren't talking about a 21 year old, who will be in his prime in FA. He's in his prime right now, actually. That prime age has gotten younger and younger for hitters, from what I've read on line.
The best 25 players should come north, and not be sent down to keep a crappy vet around, or a guy that won't contribute around, or to save service time.
That said, I don't think he's ready right now.