1. Matt Wieters, C
He could be called up anytime after April 17, and I'm hoping the sooner better. He has more hype then Markakis did, and that's because he could be the best catcher in the majors as soon as next season.
2. Brad Bergesen, SP
He is a better version of Brian Burres or Josh Towers, not great stuff, but good accuracy. He will be in the rotation by May, when one of the O's starters is really bad or injured.
3. Radhames Liz, RP
The O's converted him into a reliever, and he shouldn't need long to adapt. He could be very good, especially since he only has to throw 1-2 innings, he can throw even harder. He'll come up if a reliever gets hurt or moved to the rotation, or if the O's dump Baez or Walker.
4. Lou Montanez, OF
The O's will stick with Pie as long as he hits .200 and can throw the ball, but they could trade Scott or Freel (who could also get hurt), and Montanez would be the first one up.
Others to watch:
David Hernandez, SP
Kam Mickolio, RP
Nolan Reimold, OF