I don't expect anything from Greinke. I pitcher with "issues" who plays for KC just really seem worthy of a pickup to me.
Adam Eaton is a guy i'm going to keep an eye on. It's hard to say how he'll pitch in Arlington, but he could make a decent pickup.
Another guy to consider is Mike Maroth. He's still probably a few weeks away, but he'll have a good offense behind him. Take out his last pre-surgury start (0.1 IP, 3HR, 6ER against KC

) and his numbers were pretty good.
Tomo Ohka might be worth considering as well.
None of these are going to be huge pickups, but they might have fantasy value in the second half.