It pretty simple when you think about it. Yost wanted Bush to pitch in the bottom of the seventh, so had him bat in the top of the inning. Bush gets a hit, he's on first, and he's still probably going to pitch in the bottom of the inning. Once Bush had to run from first to third he was winded, so Linebrink comes in. You can say in hingsight "he should have used a pinch runner", but if the pinch runner had been stranded at first Yost would be criticized for wasting a pinch runner and going to our crappy pen too early. Simple indeed. So either Yost was banking on a HR, or Bush being stranded on first. Any other situation would require Bush to run, therefore getting him out of the game. I see, good strategy. Bulletin: when you are on first base, chances are you will have to run in order to advance and/or score.