Originally Posted by New York Red
The fear of extra innings.
I guess that's it. That or injury. I guess the thought is that if you have to put a second baseman at catcher, that will basically ensure a loss? Either way, the odds of the catcher having to be removed due to injury or the game going so long that a second catcher is needed is so low that it really doesn't make sense to let a solid bat waste away on the bench. But managers generally are pretty stubborn when it comes to things like that.