Heyward had been sidelined for a month after his right jaw was broken by a pitch from New York Mets left-hander Jon Niese on Aug. 21.
Heyward wore the mask on the right side of his batting helmet. He played in center field, and as planned, he played just five innings, going 0-for-2 with a walk.
Heyward says he's "not going to be as good today as I will be in five days. But you have to start the process sometime."
Information from The Associated Press was used in this report.