Actually, with Fantrax now, if an unowned MLB player is called up, they automatically go on the WW first. So fantrax would be the final authority, as once they are on WW, you can put in a claim. Ditto for DL or being sent down as well, if Fantrax qualifies the player to be Milb eligible. Although, if the player is too experienced (over 1000 AB or 400 IP), then they can not be sent down even if they are in the minors in real life.
Btw, did you get my PM?