I honestly don’t know who is the “most ready.” One would thin Johnson is......however he doesn’t look like it to me.
If he becomes the starter, then it’s probably down to he was simply the “most ready.”
I say on paper Oliver makes the most sense. Then you have (1-5) James, Bowden, Pons, Oliver and Fulk.....but that leaves Pember as really the only “relief” for Oliver and Fulk, and of he is their only relief not sure he could provide time for the 3.
I say Gaines (if he is ready which I don’t know) because that would leave Johnson and Pember to relieve 1-3, and Oliver and Pember to relieve Pons and Fulk.