As Larry says today at Viva El Birdos, "it don't look so good for Carpenter's elbow." He's going in for an MRI, and in the meantime, Randy Keisler will start for St. Louis in his place. Follow the link to VEB and read Larry's analysis of the options should Carpenter miss more than this one start. None are particularly appetizing (unless you're going to hit against them).
I'm never going to be happy about somebody being injured, but let's face it: a Cardinals team without Carpenter is very likely a Cardinals team we don't have to worry about in the Central race. Whenever anybody talks about StL, it's often, "With Pujols, Rolen, and Carpenter, it doesn't matter who else they throw out there." That's true, but that makes it all the worse for the Cards when they lose one of those three key players.