Trainer Keith Dugger and manager Clint Hurdle rushed out of the dugout to check on Iannetta, and after assuring them he was all right, he went back in the batter's box to finish the at-bat. Iannetta drew his third walk of the game on the next pitch, and three batters later, Yorvit Torrealba hit a fly ball to shallow right to score Garrett Atkins for the game-winning run.
Iannetta and Torrealba have shared catching duties this season, but a recent offensive surge has resulted in increased playing time for Iannetta. He started the past four games before being given a day off for Thursday's series finale against the Giants to rest his knee. If it were up to Iannetta, he'd be playing.
"The knee feels fine," he said. "I could play today if I had to."
Iannetta, who also singled Wednesday, had four hits, four walks and three RBIs during his string of starts, and his batting average is up to .288.
"He's taking better looks and getting better reads [on the pitcher]," Hurdle said. "They're pitching him different. Obviously, more breaking balls early in the count, not a lot of fastballs until they have to and then they're having to be specific with location."
It's the kind of production Hurdle hoped to see last year from Iannetta, when he was expected to battle Torrealba for the starting spot. Instead, Iannetta struggled, hitting .218 with four homers in 197 at-bats, and Torrealba signed a two-year extension during the offseason.
"I think last year, if you put that up against what I've done my whole life ... that's the anomaly," Iannetta said. "I'm doing pretty much what I knew I could do the whole time, and now it's showing a little more than it did in the past."
Despite battling for playing time, Iannetta insists there's no tension between he and Torrealba.
"There never will be," he said. "We get along great. We did last year, and we will this year. There won't be any issues."
Hurdle said both players are great behind the plate, but right now he's going with the hotter bat.
"[Iannetta's] had a nice run offensively in June," Hurdle said. "The challenge is consistency, and with consistency comes opportunity.
"As far as handling the staff, you don't lose anything back there with either one of those guys. They're both very professional. They're representative of what the pitchers want to do, and [they know] the best way to get it done."
Iannetta said the key to his success has been patience. Rather than swinging away, he's been more selective and looks to capitalize on pitchers' mistakes.
"I think it's not being overanxious, being able to see the ball," he said. "I've been getting myself in counts to hit in, so they [the pitchers] are a little less likely to come at the plate with something hard. It's kind of a snowball effect."
Jeff Birnbaum is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.