Bard suffered the injury during early batting practice, four hours prior to the start of the game against the Rockies at Coors Field.
"We don't know the extent of the injury, but we're a little concerned," Black said. "We are going to have the Rockies team doctor [medical director Thomas J. Noonan] have a peek at him. We'll have a better understanding of what's going on."
Bard was replaced in the lineup by rookie Nick Hundley.
Bard is no stranger to injury this season. He was activated from the disabled list on July 24 after missing 54 games with a high ankle sprain. Bard is hitting .209 this season and .278 with one home run in six games since returning.
If the Padres needed an emergency catcher, Edgar Gonzalez -- who wasn't in the lineup -- would be the logical choice according to Black. Gonzalez, normally an infielder, caught some during Spring Training, though only in simulated games.
Corey Brock is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.