Dwyer and Loaned KC Players Will Not Play vs Sporting

There's been a big debate since Tuesday night after both Sporting Kansas City and affiliate club, Orlando City, won their US Open Cup matches setting up a fourth round match up where the two would play each other. The debate was whether Orlando City's top scorer and KC's 2012 first round draft pick Dom Dwyer, and KC's 3 other loaned players (Christian Duke, Jon Kempin, and Yann Songo'o) would be able to play in the game.

Today we found out the answer to the question, and it's that they will not be able to play in the game.  The two teams had an agreement before the season, that the loaned players would not be able to play in a game should the two play each other.

I understand the frustration of Orlando City fans in this regard, but it's unfortunately the situation that it is.  MLS and KC pay Dwyer's and the rest of the loaned players salaries. 
Really this shouldn't be a surprising move to anyone.  If you look at loans around the world of soccer, the majority of them contain no compete clauses that keep the loaned player from facing off against his parent club should the two meet.  An example of this is Romelu Lukaku, who is signed with Chelsea FC.  He was out on loan this past season to fellow EPL club, West Bromwich Albion.  When Chelsea faced West Brom this season, Lukaku was ineligible to play in the match because of the terms of his loan.  So this isn't some new thing that MLS or KC, or US Soccer made up.

The problem with it is that this situation wasn't ever discussed for any of the affiliates until it happened.  And then things got confusing when New England's cup tied players didn't play for Rochester while DC did have some of their players play for their affiliate, Richmond.  A straight laid out rule for it would certainly be appreciated.  Or even make the affiliate rule the same that exists for PDL teams that are affiliates (like the Portland Timbers and the Timbers U23 team that both qualified this year).  PDL teams can't play their pro affiliate until the final.  That would at least clear up part of it and make the situation less likely.