This is a tough one. Brett Carroll is gone before we ever got to remember how to spell his name. Per Dutton & Holtzman, Caroll has been shipped to the Milwaukee Brewers. In return, the Royals will recieve cash.
It is not known whether that cash is in all coins, a mix of coins and bills, or is simply imaginary.
Extremely minor deals like this are fascinating in their own way. For example, according to Holtzman, the Royals have received, "cash consideration" from Milwaukee. What the heck does that mean? This is a fairly high-profile transaction in a multi-billion dollar industry, and as far as I can tell, the agreement boils down to, "we'll get you back at some point. Really, thanks. We owe you one." It smacks of a meaningless exchange amongst friends or, perhaps, how business was done in the Dark Ages. Still, you have to imagine they at least had to fill out forms and all that. I'd love to see those forms.
And do the future considerations ever expire? Can the Royals call the Brewers back in, say, 2015 and ask for a random amount of cash? Is someone keeping track of this? When Dayton took over for Allard Baird, was there a special moment when some octogenarian bookkeeper took Dayton into an accounts room, unlocked a drawyer, and handed him a yellowed telex form from 1975, saying, "should we need a favor from the Expos, I think the Nats have to honor this."
Carroll is a lifetime .205/.284/.325 hitter at the MLB level in sparse action.