The Pirates placed O'Hearn on the 10-day injured list Saturday with a left quad strain, Colin Beazley of the Pittsburgh Post-Gazette reports.
O'Hearn had to be helped off the field Friday after tweaking his quad while running to first base, and he's expected to remain on the shelf for roughly 6-to-8 weeks after being diagnosed with a strain. His initial timeline leaves room for him to return during the final weeks of the regular season, but the Pirates could elect to keep him out for the rest of the year depending on where they sit in the race for a postseason berth when he gets close to being fully healthy. Until then, Jacob Gonzalez figures to see more time at first base, and Rafael Flores (concussion) will come off the IL to fill the open roster spot.