I think he should not pitch a lot next year for his elbow issue, at least ST to AS break.
I am not sure which way will be better for him,
SP or DH : Need 1day rest after his pitch, and in 2018, he required 1day for preparation.
DH and RP : Need 1day rest after his pitch, but he can be at bat till he pitch.
but assign Ohtani as SP may cause bad effect to SP rotation, I am afraid.
until