The Pittsburgh Pirates placed outfielder Alex Presley on the seven-day disabled list with a concussion on Thursday and recalled infielder Jordy Mercer from Triple-A Indianapolis.
The move is retroactive to July 4, one day after the 26-year-old was jarred making a diving try for Houston Astros shortstop Jed Lowrie's first-inning fly ball.
Presley complained of not feeling well a few innings later and was removed from the game before the start of the fifth inning.
Over 60 games this season, Presley is batting .242 with six home runs and 13 RBI.
Mercer made his major league debut with the Pirates earlier this season, recording one hit and one run scored in five games.