At first, the game's announcers believed it had smacked off one of his shins -- but when the replays showed it went directly into his family jewels ... they knew exactly what was going down.
Nootbaar, meanwhile, was in a world of pain ... he writhed on the ground for several moments -- before he somehow got up. He would go on to strike out during the at-bat ... and then leave the game to get all checked out.
It's unclear exactly how the guy is now doing ... the Cards only said afterward he was removed "due to a lower abdomen contusion."
To add insult to injury, Nootbaar's Cardinals lost 8-0.