The Yankees were "not guilty as charged" in Saturday's game. Or maybe one should say that this was true for a particular Yankee. But they paid the price, not only within the game itself, but probably for the rest of the season.
The "charge" was that Mark Teixiera made the third out at first in the bottom of the ninth inning. An instant replay showed him to be "safe." But the umpire's ruling that he was out stood, meaning that a run that had crossed the plate was not counting as the tying run in what was left as a 5-4 game against the Baltimore Orioles.
In order to get what should have been a "safe" call, Teixiera slid into first base on his bad (left) leg, thereby re-injuring it. He did what he could to avoid being called out, and preserve the run, objectively succeeding. But his (and the team's) worst fears were realized when the umpire ruled otherwise. They got the worst of both worlds, an immediate loss and likely Teixiera's exit for 2012.
If Teixiera can't play, his likely replacement would be Steve Pearce, a journeyman who has been bounced around several teams this year. Because Pearce is a HUGE drop-off from Teixiera, the difference over the remainder of the season, could easily be one game, possibly more.
If Saturday's game had been tied at 5-5, the Yankees would have been slightly better than even money to win it (with their extra out). And in a race that is as tight as the current one, those one or two games could well mean the difference between the division championship, a wild-card slot, or nothing at all.
With few exceptions, Yankee players are older, more powerful and more seasoned than those of most other teams. These characteristics also tend to make them less agile, which is to say that they are more likely to get hurt, and may take longer to heal than younger players. So they can take fewer chances, and the consequences of the chances they do take may be more severe.
With the benefit of hindsight, it would have been better that Teixiera's heroics hadn't occurred. The Yankees might have lost the "half" game in extra innings. Meaning that their first baseman might have done better service later in the season.
Sometimes, "discretion is the better part of valor," particularly if you a recently injured player who has barely recovered. And particularly if you are a Yankee, a team that has suffered more than most from injuries recently.