I could see him piggy-backing Aceves and Buchholz in a game with Buchholz coming out of the pen. I think Aceves would be the starter, not Buchholz.
As for Lackey not making the post season roster, I don't think there is a chance of that unless he gets injured. I'd be willing to wager on that one. If they leave anyone of the post season roster, it should be Wakefield. He's completely useless at this point.