I wouldn't fire him. From the outside, it doesn't feel like it's the time to do it. An epically bad September, but you still won 89+ games and are in it going down to the end. He has an excellent track record in Boston and I'd give him a reprieve on this year. If things don't start off well next year, then something might be warranted. Losing Buchholz, Youkilis, and Bedard for various lengths of time didn't help. Lester having 3 straight bad outings, or Beckett getting bombed by BAL in back to back starts, is hard to explain... bad luck, if anything. And they could still make the playoffs.
And getting off the Red Sox, but what a horrendous loss by STL. A win over basement-dwelling HOU would have tied them for the wild card (ATL lost). Instead STL loses in extra innings. Losing to Houston is bad to begin with, but considering the circumstances, it's almost impossible to swallow if you're a STL fan. A huge opportunity out the door.