I like the idea of buying low on Gray but when it's only for one year I don't know if it makes a ton of sense. If he has a great year then he leaves at the end of the season, if he's mediocre then he would have been blocking a young starter from auditioning for a role in the future.
Cahill on a cheap 1-2 year would be alright provided that he can still reach 150 innings if necessary.