Pittsburgh, PA (Sports Network) - The Pittsburgh Pirates placed infielder John McDonald on the 15-day disabled list Wednesday due to a lower back strain.
McDonald, who is batting just .065 (2-for-31) in 16 games this season, sustained the injury during Tuesday's extra-inning victory over Milwaukee.
The Pirates recalled infielder Jordy Mercer from Triple-A Indianapolis to fill McDonald's spot on the active roster.
Mercer had just been sent back to the minors when the Pirates activated second baseman Neil Walker from the DL on Monday. The 26-year-old had a two-homer game in a win over the New York Mets this past Saturday, and belted three homers in 31 at-bats while batting .258 over a nine-game stint prior to being optioned.