In Greg Schaum's post-game show on 610, he reported the following story which is disjointed and full of holes due to the fact that I don't think anyone, including Schaum knows even half of what is going on here:

In spring training, Royals pitching prospect Dan Gutierrez roomed with Scott Boras clients Mike Moustakas and Eric Hosmer.  Sometime this spring Gutierrez switched agents and became a Boras client.  Also this spring, Gutierrez has been rehabbing from some sort of non-major injury (which is why he's been in extended spring training and not assigned to a minor league team).  Apparently some conflict arose recently between the Boras/Gutierrez camp and the Royals about who Gutierrez should be working out and rehabbing with.  Boras/Gutierrez wants it to be their guy and the Royals want it to be their guy.  The conflict has gotten heated enough that the Royals have "sent Gutierrez home for personal reasons."

End of story.  We have no more details at this time.  Check comments for more information as it becomes available.