Positioned right next to the New York Yankees' dugout on the first-base side, Pete Stendel of YES Network was struck by a hurried throw from Henderson, who fired high to first as he tried to complete a double play in the fifth inning.
After the game, YES said Stendel was conscious and undergoing tests at a local hospital. No further updates were expected from the network Wednesday night.
"Every time that a ball goes over the first baseman or even a foul ball from the hitter, you don't want to see it going towards a fan. It just happened to be in the wrong spot, and I hope he's doing all right," Henderson said following his team's 6-3 victory. "My prayers go out to him. I'm just thankful for the guys that rushed over there to him to help him."
The game was delayed about 17 minutes as the Yankees' athletic training staff and medical personnel tended to Stendel in the camera well. Baltimore players came off the field and waited in their dugout as Yankees and Orioles, including Henderson, watched in obvious concern at a hushed ballpark.
"That was scary. I think I speak for all of us when I say our thoughts are with him. Hope he's doing all right and he's feeling better and we see him back here soon," Yankees outfielder Jake Bauers said. "He had a pretty bad reaction when he got hit, so it was scary to see."
Stendel was strapped onto a stretcher and carted off the field, raising and wagging two fingers to loud applause from the crowd of 36,022 as he was driven along the warning track behind home plate.
"Definitely praying for him. It was good to see him obviously coherent and obviously raising his hand going off," Yankees manager Aaron Boone said. "But I saw it pretty well right away, and it was very scary. I didn't see how he fell back, but I knew what could've been possible falling back, on top of the impact from the velocity of the ball hitting him. ... Obviously, a difficult scene there, and just hoping he's OK."
Baltimore manager Brandon Hyde also said it was a frightening scene that was "awful" to be a part of.
"He gave the peace sign coming off the field, but that was tough to watch, and hopefully he's OK," Hyde said.
Baltimore starter Dean Kremer was given several warmup pitches before the game resumed. Henderson was charged with an error that allowed Anthony Volpe to reach second base. Volpe scored on Kyle Higashioka's two-out single to give New York a 2-0 lead.
After the game, Henderson was asked whether he was shaken up.
"I'm doing pretty fine. Yeah, it sucks that happened to him, but it's just trying to play the game hard. Sometimes that happens," he said.
The Associated Press contributed to this report.