Decisions like this are a blend of art and science. My momma always said, "We'll cross that bridge when we get to it." So I think you make a general plan and adapt as the circumstances call for it and as things play out.
Odorizzi shows us that not every inning is equal, since he's been averaging 18.6 pitches per inning, so I like Jeremy's approach of looking at pitches thrown. And 2400-2500 seems about right for the year.
That leaves Romero in the neighborhood of 1250 pitches remaining. If you ballpark 90 pitches per start, that's around 14 more starts. So keep that in mind and see how things play out over the next month or so. Considerations in that are:
- Staying on the current 5-man rotation with no rainouts gives Romero five starts -- June 22 and 28 and July 3, 8 and 13 -- before the all-star break.
- How's Santana doing? None of the current guys has really pitched himself out of the rotation. If Santana or May gets to the point of being ready, it only takes three starts by one of them (in a six-man rotation) to save a start before the break. Or two starts and a rainout, etc.
- If that doesn't happen, move Romero to the back of the rotation coming out of the break, which essentially is the same as skipping a start.
- If all five current guys are still healthy and pitching effectively when (if) Santana (or May) are ready, go ahead and go to a six-man rotation for a few times through the rotation and see how things go.
- By that time, you also have a pretty good sense of whether you're buyers or sellers. If sellers, and everyone is healthy, Lynn's going to be a trade candidate.
- And if sellers, that also means that it's pretty easy to shut down Romero when it seems appropriate based on fatigue and effectiveness.
In a best case scenario (the Twins are still in it and guys are healthy), I think Romero would be a good candidate for the bullpenning approach. I'd think about pairing him with Odorizzi, since Odorizzi seems to particularly struggle with the third time through the order. But to keep Romero on a regular preparation pattern, consider starting him and letting him go two innings. Often, that would bring Odorizzi into the game at the bottom of the order, so when he starts his third time through, he's starting with the 7, 8 or 9 hitter. Similarly, two innings of Romero and five of Odorizzi gets us to the eighth inning and very close to the FRE, so it (in theory) also provides a lighter day for the bullpen.