I really couldn't guess on ERAs, but for the non-active one I'd guess Clemens;
I am 90% sure it's not Clemens - while he played all the way through 2007, he had a couple half-seasons in there, and even when he was full-time for Houston, they didn't score any runs for him.
Since this is probably some sort of timely comparison, I'm going to guess that the inactive pitcher is Glavine.
edit: nevermind, you posted while I was thinking.
Is the third guy Petitte? Zito? I doubt that since both of them have had at least a few 4.00+ ERA seasons...
edit2: I bet I got it - Petitte and Clemens former teammate - Roy Oswalt?
I do not understand what I do. For what I want to do I do not do, but what I hate I do.