Reports out today that Sporting KC will be bringing in another defender on trial in the month of June. That player is 16 year old defender, Alexis Velela, a defender for the US U17 national team. He's captained the team on a number of occasions.
Velala has been in the US Soccer residency program, but recently hired an agent. Velala apparently has multiple professional options.
If KC wants to sign Velala, the acquisition process would need to be sorted out. Since he's on trail the assumption would seem to be that Velala would not be a Generation Adidas player or previously offered a contract by MLS. Because if either of those occurred, then Velala would be required to go through a weighted lottery (unless all other teams pass, in which case he could be claimed as a waiver). In this instance it would appear the more likely acquisition process would be as a waiver selection or discovery signing.
From looking at some of his previous matches, Velela appears to be an outside back. If KC were to end up signing him, it'd give Sporting three teenager defenders on their roster, joining Igor Juliao and Erik Palmer-Brown.