ST. LOUIS -- Having already snared a line drive at his face while on the mound in the fifth, Michael Wacha ended up being knocked out of Wednesday night's start, not by Arizona's hitters, but by one of his own an inning later.

Unable to dodge Matt Adams' sharp foul ball into the Cardinals' dugout, Wacha took a hit just above the back of his right elbow. The ball struck a nerve, leaving his pitching arm numb for what he estimated to be about 30 seconds. It was enough for manager Mike Matheny to end Wacha's start after 88 pitches. The Cardinals later categorized the injury as a contusion.

"[I'm] just sitting in there and then all of a sudden I hear, 'Heads up,' and at the last second, I see a ball flying into our dugout," said Wacha, who was screened from seeing the ball by teammates who were standing up near the dugout ledge. "I kind of jumped out of the way because it looked like it was going to square me up in my chest. As I was getting up, it ricocheted off the wall and hit me in my back elbow. The hand just goes numb, and I didn't really know what was going on."

Wacha, who had his arm wrapped with ice following the Cardinals' 3-2 win, said that there was swelling and seam-marks at the area where he was hit. He expects to have a better indication of whether his next start could be in jeopardy when he plays catch on Thursday. As it is, Wacha is in line to open the Cardinals' series against the Yankees on Tuesday at Busch Stadium.

"His status is he's going to be fine," Matheny said. "It was just tightening up a little bit and we weren't going to take the risk. He was throwing the ball extremely well. We'd have liked to have thrown him back out there in the seventh, but didn't want to take any chances."

Wacha allowed two hits in six scoreless innings. He's allowed no more than three runs in any of his 10 starts, and it was the eighth time Wacha had pitched at least six innings.

As inconvenient as it was to be in the path of Adams' foul ball, Wacha could have truly been knocked out had he not reacted quickly enough to get his glove up on Martin Prado's line drive up the middle to lead off the fifth. Wacha made the catch as he was falling forward.

"That was equally as scary, probably even more scary coming right at my face," Wacha said. "I was just protecting my face, just trying to get a glove up in time. Lucky enough, I was."