FC Dallas had the chance to sign an international defender but passed. Gustavo Cabrera of the Guatemalan national team and Comunicaciones tried but failed to latch on to FC Dallas. Despite not exactly featuring a wealth of defensive talent, FC Dallas brass apparently felt they could do without the services of a Guatemalan defender.
Of course, it's not just his skill level that has to be considered here. Cabrera would take up a senior international slot, and you don't want to use those on just a marginal or decent player. I've always felt teams should maximize their senior international slots and I don't know that Cabrera would fit that description.
Still, Cabrera must really have not impressed because FC Dallas' defense is shitty no matter if they play with six defensive midfielders.