Crawford reached on a fielder's choice in the top of the first and was leaning off the base when Orioles rookie Jake Arrieta threw toward first. The ball eluded the grasp of first baseman Ty Wigginton and hit Crawford between the legs.
He rolled off the base and was tagged out.
Crawford remained doubled over for several minutes before finally walking off the field with help from trainer Ron Porterfield.
"Carl Crawford is one of the toughest guys I've ever played with," Wigginton said. "He's a true gamer, and if that guy don't bounce up, it's not good."
Crawford was taken by ambulance to a hospital, where tests were negative.
"You couldn't hit it in a better spot. It just took the wind out of me," Crawford said. "Right now it's real sore, but the doctor said there was no damage. I'm guessing I'll take [Wednesday] off."
Crawford said he doesn't wear a protective cup because it's too restrictive, and he insisted he won't change that practice.
Information from The Associated Press was used in this report.