You develop your bullpen, and trade for a hot hand down the stretch. Betting big money that anyone but the elite will have a repeat above average season seems pretty foolish. Given we already have Perkins May and Jepsen we only need to really find 2 others, if your willing to go with Berrios and he meets expectations now you're down to one. You should find the other in Spring Training, but if not a minor trade can do the trick. I know you want Berrios and/or May in the rotation but the point is you can build a great bullpen without spending money and without downgrading the current rotation. If Berrios is an ace starter thats almost like an addition to the bullpen by keeping them fresh every 5th day especially when the offense does it's job, if he's not an ace starter he's probably better used in the bullpen, the same is true for May. Seeing other teams have shut down bullpens doesn't mean you have to have a shutdown bullpen. A bullpen ERA of 3 means while the Royals and Yankees give up more then zero you give up 1 from the 7th inning on, you should be able to build a roster that can make up that run elsewhere.