I seem to recall the following. Under normal circumstances, a player on loan only counts against the salary cap to the extent of the salary paid by the MLS club. However, if the loan is from an affiliate, then the MLS club has to recognize the full compensation for that year as if it owns the player. I think this would include at least an amortization of the acquisition cost.
So, no idea if we will have to count this guy as a DP. If we do, he would only be a Young DP, and at 19, that means he would only count $150K against the salary cap.
This could also be one of those situations where he counts as a DP for the first half of the season and then is a TAM player once we get a summer transfer.
Maybe a half year loan. Who the hell knows anymore