O'Brien (undisclosed) was placed on the 10-day injured list Thursday, Andersen Pickard of MLBDailyDish.com reports.
The reasoning behind O'Brien's move to the injured list is not clear. The 29-year-old, who owns a career .209/.275/.434 slash line across 200 major-league plate appearances, joined the Braves as a non-roster invitee in January and will serve as organizational depth once healthy.