There are 41 players still in Major League Camp, which means sixteen more have to go. Let's give this a shot (and we're counting players who could begin the season on the DL):
Infielder Locks:
Lance Berkman
Kaz Matsui
Tommy Manzella
Pedro Feliz
Jeff Keppinger
Geoff Blum
Outfielder Locks:
Carlos Lee
Michael Bourn
Hunter Pence
Jason Michaels
Catcher Locks:
Humberto Quintero
Rotation Locks:
Roy Oswalt
Wandy Rodriguez
Brett Myers
Bud Norris
Bullpen Locks:
Brandon Lyon
Matt Lindstrom
Jeff Fulchino
Chris Sampson
Tim Byrdak
Brian Moehler
Felipe Paulino
So that right there is 22, meaning there are three spots still open.
Quintero isn't going to be the C1, so right now I'm giving the C1 edge to J.R. Towles (23). He has shown enough this Spring to give the Astros some breathing room in how quickly they promote Jason Castro. Castro goes to Round Rock, Towles begins the year at Houston, and Quintero is officially in the sweat box.
With the 5th Outfielder position, Jason Bourgeois and Cory Sullivan are locked in a death struggle, but Sullivan (24) gets the late nod for a couple of reasons: Bourgeois has been slowed by injuries to both hamstrings. That's troubling, but it also sat him down when he needed opportunities to show what he's go. Also there's the natural selection of Sullivan being left-handed, which adds to his favor.
This leaves one spot. Notice I put both Paulino and Moehler in the bullpen, and this could change. If Paulino doesn't win a spot out of Spring Training, I think he goes to Round Rock, and Moehler goes in as SP5. If they both stay, I could see Gervacio (25) getting the final bullpen spot. Wesley Wright is also in the mix, but I could see the Astros sending him to Round Rock to continue his progression into a starter.