Hate to say it but I was thinking the same thing when watching him yesterday. You don't see many guys maintain that type of stuff without hurting themselves.
1. He was a better starter in 2015 than he was a reliever in 2016. 2. Starters are more valuable 3. He mentioned that his body didn't respond well to pitching nearly every day as a reliever and may have led to his back problems.
I'm filing this under "good problems to have" but how will this rotation look when Santana and May get healthy? Berrios Romero Gibson Odorizzi Lynn Santana May May is the obvious guy to push the bullpen but I really like him better as a starter. I think Lynn starts pitching better here and will be tough to bump out of the rotation. There will always be injuries but it will be interesting to see how Molly handles this moving forward.
Closing, like pitching in any other inning, is just pitching. So he can definitely close. Molitor has to start using him in higher leverage situations.