Rooker is out of the lineup Wednesday at Cleveland.
Seth Brown will serve as the A's designated hitter and bat third versus the Guardians and young right-hander Gavin Williams. JJ Bleday is starting in left field and hitting fifth. Rooker has gone 1-for-17 with 10 strikeouts across his last five games and his season OPS has dropped from .984 to .832 over the last four weeks.