Contreras has the stuff to be a nasty closer. I'm sure the league will figure out Shingo next year (even if they do, Shingo will still be effective) will I like the set-up as well.
Marte
Shingo
then Contreras to close it
But I'll like it better if we get a starter for FA. If not, leave Contreras as a starter and Shingo as the closer for next year. But I'll be more focused on this year and worry about next year down the road.