Lucas Harrell and Bud Norris are in. That much we know. SP 3-5? We don't know so much.
Here are your candidates:
Jordan Lyles
Good God his Spring Training has been rough - and while you don't typically put much stock in Spring Training starts (for reasons previously explained), Lyles' 19.13 ERA/3.38 WHIP is not encouraging. In 8IP this spring Lyles has allowed 26H/17ER. He's only walked one batter, so the issue seems to be that all the batters know what he's doing, all the time. Lyles also has options left, so he wouldn't have to pass through waivers.
Alex White
White is one of three pitchers (as of 10:15am on March 16) to throw 10+ IP, and he's allowed 17H/8ER in his 10.1IP. Opponents are hitting .362 against him thus far, and he has a 2.03 WHIP. That said, in his last start against the Nationals on Thursday, White threw 4IP, 7H/2ER, 1K, and Jason Castro raved about the late life in his sinker.
Phil Humber
Has thrown exceptionally well. With a team-high 14IP, Humber has only allowed 5H/2ER, with 7K:4BB. On Monday, he threw 5IP, 1H/0ER, with 3Ks. Humber is also out of options, meaning if the Astros were to send him to OKC, he'd have to go through waivers first and I think his spring has been strong enough that there's no way he doesn't get claimed. I'm putting Humber in the rotation.
Brad Peacock
Peacock has really come along, pitching very well in his last start - allowing 4H/1ER, 5K:4BB in 5IP. 54 of his 80 pitches were for strikes. Porter was extremely complimentary, throwing his breaking ball for strikes when behind in the count.
Erik Bedard
Bedard has been limited this spring, only throwing 3IP thanks to his strained Bedardadonk. He threw an inning on Wednesday and will throw again on Sunday. There are two sides to this one: not throwing means he might actually stay healthy longer, or he could get edged out simply because the Astros haven't seen enough of him in game action. Bedard addressed this possibility after his appearance on Wednesday, but Porter likened him to Jamie Moyer - using craft and deception to get through his outing - and made special mention of hoping that the young pitchers (which narrows it down to "Everybody Else") were paying attention to how he worked. Could get a spot simply as a matter of Veteranism.
Dallas Keuchel
Another tough one, simply because he has options left and hasn't had a great Spring, throwing 7IP and allowing 7ER. That said, he's really the only LHP option out of this whole group. Out of every pitcher the Astros currently have in camp, he's one of two lefties (Bedard) to be a candidate.
John Ely
John Ely is a distinguished member of the double-digit ERA club, joining Jordan Lyles thanks to his 10.13 ERA. He also has options left, so he might just find himself back in the Pacific Coast League to start the season, with a go-bag packed to join the Astros.
So there you have it. How do you fashion a rotation out of that? If we're going based on Spring Training results alone (dangerous), your rotation might look like this:
1. Norris
2. Harrell
3. Humber
4. Peacock
5. Keuchel (lefty).
The other question is, where the heck is Luhnow going to put the guys he sends down? OKC's rotation could be jammed up, as well. Rotation candidates for the RedHawks include Jarred Cosart, Rudy Owens, Ross Seaton, Brett Oberholtzer, Jose Cisnero, Paul Clemens (who may actually move to the bullpen for Houston), and Asher Wojciechowski.
Allow me to do the math for you: We've looked at seven pitchers for three spots, leaving four guys who aren't going to make the Astros' rotation. If Bedard doesn't make the rotation, he'll probably just be released, which would leave three starting pitchers heading down to OKC, where there are six guys already there to challenge for a rotation spot.
Update: The commenter below is correct (and I can't find the link right now): Luhnow did say at some point this off-season that OKC will proceed with two starting pitchers per game.
I do think Humber is a lock for the rotation. So who do you pick for SPs 4/5?