But I'm fairly sure that I remember that it was the Nats who made that decision and announced it prior to the draft (since it was know that we were going to draft him). Boras has no authority to make any such decision.
Although I suppose it could be argued that Harper does. Even then, I'm not sure. Does a player have the authority to determine what position he plays? Look what happened to Soriano.
The Nats made the decision, I read an article about it
And I'm sure Bryce was in favor of whatever position gets him to the majors faster