Reynolds (back) is serving as the designated hitter and batting second in Sunday's game against Seattle, Danny Demilio of PittsburghBaseballNow.com reports.
Reynolds sat out Saturday's contest due to a sore lower back, but he's back in the lineup for the series finale. Since the All-Star break, he's slashing .282/.365/.365 with 10 runs scored, one home run, eight RBI and a 30.2 percent strikeout rate across 95 plate appearances.