But it's at least worth watching his progression for the remainder of the season. In a loss to the Marlins on Friday, Oswalt's fastball lacked its usual life, hovering around 89-90 mph six days after it topped out at 94 while he was striking out nine in Washington.
Oswalt, who missed six weeks this summer because of a back injury before returning earlier this month, got defensive when asked about the dip in velocity.
"I don't make no big (deal). That's you guys. That has nothing to do with me," Oswalt said. "That's you guys (who) watch the radar gun. I looked up a couple innings and saw 91 and 92. I threw 93-94. Two miles an hour difference. Ain't no big difference."
Oswalt said he made "just one bad pitch" on Friday. He threw a slider that didn't slide to John Buck with the bases loaded in the sixth inning. Buck drilled the pitch into the right field seats, turning a 2-1 Marlins lead into a much more comfortable 6-1 advantage.
But Oswalt's outing was about more than one batter. He allowed 12 hits - five for extra bases - in 5 2/3 innings.
"He had a little bit more crispier stuff in Washington," manager Charlie Manuel said. "He had trouble getting ahead of the hitters, and it also looked like he had a hard time getting the ball inside on the guys, or he didn't have nothing when he threw it in there."