It feels like only a matter of time until a six-man rotation becomes the norm around baseball. Individual pitchers are generally throwing fewer and fewer innings with each passing season, and with a full-time 26th roster spot seemingly on the horizon, soon it’ll be much easier to carry that extra starter. Right now it takes a little roster creativity to make a sixth starter work.
The Yankees, like many teams, have used a spot sixth starter at times the last few years. Someone gets called up, makes one start to give the rest of the rotation an extra day of rest, then gets sent back down the next day.