He won't be added until he plays in his first game. The others were added (ie: Mauer, Kaz Matsui) because they opened the season on the ML roster. But ya never know with Yahoo, it could be a week or two after his first game. From what I remember, they took a while to add Prior.
"Jack, will you call me, if you're able?"
"I've got your phone number written, in the back of my Bible."