They Sox are reportedly thinking about starting Lester on short rest. He hasn't been wonderful lately on regular rest, and he's never tried to go on short rest before. Maybe there's an alternative we haven't thought of.
Obviously, Aceves has been discussed, but Tito seems firm in holding him to one or two innings every two or three days.
How about Miller? In two appearances against Baltimore he's 2-0 with a 2.53 ERA. Sure, he was very inconsistent as a starter, but he's only been used sparingly of late out of the pen. Perhaps the rest will allow him a quality start. If he doesn't work, you can pull Aceves in, or even Lester if necessary.
I'd rather save Lester on full rest for the potential playoff of Wild Card game to give him his best chance at full effectiveness. I think a rested Miller will be better than a tired Lester.
As an alternate plan, maybe we shouldn't think in terms of a starting pitcher and go with a full bullpen game - 1 or 2 innings each for Weiland (which is clearly when he's most effective), Aceves, Morales, Bard, and Paps with Miller and/or Atchison thrown in as needed. We'd lose some of the lefty-righty switch flexibility, but our pen has been more effective than our back-end starters lately.
Whatever alternative Tito decides I hope it's not a tired Lester.