With two on and none out in the bottom of the fifth, Mark Teixeira came up and hit a groundball to third. And on his way down to first base, he grimaced and pulled up, holding the back of his leg.
Yankee trainers came out of the dugout and helped Teixeira off the field. From the looks of things, his right hamstring tightened up, and he's been replaced by Marcus Thames at first. The Yankees, obviously, will hope that Teixeira is okay, although it is worth noting that he remains hitless in the series.
It is very possible that Mark Teixeira will not make another appearance in the ALCS.