NOT a boston fan at all, but at the begining of the season it was Arroyo who was considered to be in his spot, and is the canidate who will have to prove something to not go to the pen. That said, if Wakefield is doing poorly at the time, it could be him as wel (USA Today) --
So, if Miller came back today, Arroyo would go down
In a month more, if Arroyo is rockin and Wakefield struggling, it will be Wakefield.
If youre asking for a bet, Id say Arroyo goes down, I think it makes more sense to have him in MR than wakefield.