One thing to remember about possibly trading Greinke, though, are the new free agent compensation rules. In order to get comp picks, you need to make a qualifying offer on that player, and you can only make a qualifying offer if the player was on your team for the entire season. Any team that would trade for Greinke would be unable to get compensation picks for him, meaning the return for Greinke likely wouldn't be as great as it would have been under the old rules. In other words, they won't be getting the equivalent of what they gave the Royals to get him. If they wanted that, they would have had to deal him over the winter. Midseason blockbusters are pretty much dead, unless the team trading for the star player thinks they have a good chance at keeping him or you deal with a GM who isn't very sane.