Oh, okay. I see what you mean now. You have 7 "spots" in the minors (not necessarily rookies).
I'm not sure what the problem is, then. Why would you want to have one more player sitting down in the minors?
By the way, you know you can send down your scrubs and call up all your rookies, right? The rookies will have a combined actual salary of around 8-12M, so it's worth it to draft 8 200K scrubs and send them down permanently in order to bring up all your AAA.