Here is what I would have done without having to risk losing anyone via DFA and secondly not needing a starter for Thursday:
1. First of all, Breslow only threw 1/3 of a inning, and Miller 2/3. Assuming Mortensen is okay, those three guys would be available tonight.
2. Bring up Aceves and put Buccholz on the DL. He'll miss an extra start, but given the neck issue, give him the extra rest.
3. Push Lester to tomorrow in Morales start. This gives Lester an extra day of rest and puts the other starters back on normal rest. Dempster goes Thursday, Doubront Friday, Lackey Saturday.
4. Pitch Aceves tonight. He's got a rubber arm and hopefully he can give you 6 innings. He will probably give you more innings that Lester.
This allows you to keep your entire bullpen intact, have Breslow, Miller and Mortensen tonight, and only need one additional starter.