The process that brought him in was a little unexpected, but the end result really wasn't. Today, Sporting KC acquired the rights to former San Jose Earthquakes draft pick, Michael Thomas for a 4th round Supplemental draft pick, the 73rd overall. The fact that Sporting had to give something to San Jose for Thomas is the surprising part.
I'm not sure why KC had to give up a draft pick for Thomas. Thomas was originally drafted by the Quakes in the second round of the 2010 MLS Superdraft. According to MLS' rules, San Jose held his rights through 2 December 31st's. This means their rights to Thomas expired on December 31st, 2011. So the question becomes why Sporting had to give up anything to get the rights to Thomas?
The rule states: "Unless claimed on waivers, a player who was drafted by a particular team through the SuperDraft or supplemental draft and did not sign with the League, is placed on that team’s “College Protected List” until the second December 31 following the draft in question, after which the team loses the rights to the player."
So it doesn't make sense why a trade had to be made, unless the trade was officially made last year and just not announced until today.
The unsurprising part is that KC was looking to acquire Matt Besler's college roommate. Thomas had played for KC in the last reserve league game of the season last year against FC Dallas. And rumors out of Sweden had been linking the midfielder with a move back to the US. Thomas will very likely be in camp once preseason starts for KC.