I have Middlebrooks on my minor league roster in the keeper league. He's hot and I could certainly use power. However, if I promote him, it counts as the first year (we can keep players for up to three years, or four or five for a huge budget increase), and I can't send him back to the minors if he gets demoted or benched in real life, meaning he might become a dead roster space. What would you do?

You have to keep him in minor spot until you have more information, you'll regret if he get sent down next week. Other option is to use him as trade bait as a minor keeper for now power.

keep in the minors.. his time in the majors is too unpredictable, and he's far from a lock to continue to put up #s

I think you guys are right. I need every bench space for streaming pitching.