As part of the Rockies 6-4 win over Arizona at Coors Field, Arenado launched a solo homer in the sixth -- but not before colliding with McKenry on a foul popup in the top half of the frame.
"I told him I'm going to head-butt him tomorrow too," McKenry said with a laugh. "So we'll go with that."
At the time, though, the collision was no hearty matter. With two outs and the D-backs leading, 1-0, Chris Owings popped up a 91-mph fastball right in front of the Arizona dugout. McKenry was camped under the ball as Arenado came charging in. But just as the Rockies catcher squeezed the third out, the two crashed, and both ended up on the ground.
"I got underneath the ball, and he called me off real late," McKenry said. "At that point, you're kind of stuck underneath, and he's aggressive -- that's what you want out of him. I think we both did it right, but at the same time, it just looked, really, really bad.
"It rung my bell pretty good, and it rung his bell pretty good too. But we're two tough guys. We didn't want to leave the game. We weren't going to leave the game."
McKenry got up first, but Arenado remained kneeling as Rockies manager Walt Weiss and head athletic trainer Keith Dugger checked on him in foul territory near home plate.
After a few minutes, Arenado eventually walked off the field under his own power, and Weiss said postgame that his third baseman hadn't suffered anything severe.
"On a popup, the crowd noise starts to get loud," Weiss said. "Nolan called it, and I don't know if Mac heard him or if Mac heard him late. Nolan got hit kind of in the throat, the collarbone and had the wind knocked out of him. He checked out all right in between innings, and went up there and hit a homer.
"He's certainly got the flare for the dramatic."
Dargan Southard is an associate reporter for MLB.com.