The Pirates on today put John McDonald on the 15-day disabled list because of a strained lower back and recalled Jordy Mercer from Class AAA Indianapolis.

McDonald's back tightened and forced him to leave Tuesday's game after entering as part of a double switch.

Mercer joined the Pirates when Neil Walker went on the disabled list but was sent back to Indianapolis Monday.

First Published: May 15, 2013, 10:15 p.m.