Arenado (back) will serve as the Cardinals' designated hitter and No. 4 batter in Sunday's game against the Reds, John Denton of MLB.com reports.
After he was held out of the lineup for Saturday's 11-3 win with lower-back tightness, Arenado ended up pulling out the upcoming All-Star Game, with Atlanta's Austin Riley called upon to replace him on the National League roster. Though Arenado showed enough improvement to re-enter the lineup in a non-defensive role for the Cardinals' final game of the second half, he'll still sit out the Midsummer Classic. The back injury has lingered for more than a month, but Arenado expects that the time off during the break will allow him to be healthy and productive throughout the second half, according to Denton.