Much like the small sample size of April, spring training statistics are essentially worthless. The Braves are rushing Teheran along entirely too quickly and he was pretty clearly having mental issues last year; batters were able to flat-out abuse
him in AAA throughout 2012.
I think the Braves should have sold high on him (I'm still surprised he wasn't part of the proposed Dempster trade) considering how much his prospect value fell over the last year, but at the very least he needs a half-season in the minors to prove that he can beat AAA pitching consistently. Rushing him to the majors is probably the worst thing they can do to him, and Frank Wren being Frank Wren means they'll probably call him up in May.