It's entirely possible this will be the Braves' worst starting rotation in 25+ years. Last year's group of starters, which had a 4.41 ERA, was really bad, and now we remove Shelby Miller from the mix.
Other than Julio Teheran, there are no sure-things. Teheran will be the club's No. 1, and the Braves need him to be the Teheran of 2013-2014 or things are going to get ugly.
Everyone seems to think Bud Norris is a lock for the rotation. I'm not so sure; granted he would need to get blown up in a couple of starts to put him on the bubble, but there's a reason he was cut mid-year by the Orioles. He owns a career 4.44 ERA and a worse FIP, and while Roger McDowell has brought a few veteran starters back to life in Atlanta, expecting anything more than 5th starter numbers out of Norris would not be smart. Best-case scenario is 2014 Aaron Harang.
Matt Wisler had his struggles as a rookie and was absolutely pounded by left-handed batters -- they hit .320/.416/.569 against him. Righties were far less successful, and Wisler going to changeup-master Tom Glavine for advice is encouraging. He will need that pitch in order to be successful in 2016 or teams will stack lefties against him.
The final two spots appear to be wide open. The Braves would prefer for their young kids win the jobs (Manny Banuelos, Williams Perez, Aaron Blair, Tyrell Jenkins and Mike Foltynewicz, who is still regaining strength from a serious blood clot injury, Ryan Weber) but will have some veteran options, too (Jhoulys Chacin, Kyle Kendrick).
My guess is the battle for the final two rotation spots goes down to the wire, and all of the guys listed above make starts in the regular season at one point or another. There's light at the end of the tunnel, but we may still be 12 months away from it.