They can skip a few turns too if they want. Not great news but it does give them the ability to be more decisive - if Walker can't reclaim his spot maybe they do have to get another Thor or Lorenzen.
But, bullpen games and Allard (seems to be back on point) or Philips also options, if the lead is still good and they are just trying to eat innings until October, when they won't even need a 4th starter until NLCS.