That is tough. I would just accept you have a good pitcher and move on.
Otherwise it's a lot of work to break it down. What you would have to do is run the recs for your rook, find out his hitting numbers as they could help, but not likely. The you have to run his pitching recs under every scenario. Closer, set-up, long, mop, maybe even a starter in different rotations. Then you must do the same with the real candidates...
Me, I'd just accept he is good.