SP2: Jarred Cosart
SP3: Brett Oberholtzer
SP4: Lucas Harrell
SP5: Dallas Keuchel
I understand Keuchel's inclusion, as he's a lefty, but I'm trying pretty hard not to get riled up about Lucas Harrell's inclusion over Brad Peacock.
Harrell posted a 7.50 ERA, allowing 24 hits and striking out just three batters this Spring, but - in an effort to be positive - did have his numbers hijacked by a mid-March start against the Tigers in which he allowed 12H/9ER. You can read Jose Ortiz's profile on Lucas Harrell from March 14 (the day before the Tigers start) here, in which we find that nobody really liked Lucas Harrell, and Lucas Harrell didn't really like anybody else on the 2013 team.
You look at Dallas (Keuchel), we just felt like the time he spent in the rotation was much better than the time he spent in the bullpen. And I felt like Peacock has that power stuff that can actually play as a long reliever. Or in a situation where the starter gives us extended innings, he's another option in short relief, as well.
Ultimately, it's not like this doesn't have room to change. The Astros used 10 starting pitchers last season (Bedard, Lyles, Keuchel, Harrell, Norris, Peacock, Oberholtzer, Cosart, Humber, Clemens), so this is how it shook out in Spring Training.