Mountcastle is out of the lineup Sunday against the White Sox, Roch Kubatko of MASNSports.com reports.
Mountcastle missed a few games due to a hand injury before rejoining the lineup for Saturday's doubleheader, and he went 1-for-6 a triple, a run and five strikeouts across the twin bill. Trey Mancini (elbow) will serve as the designated hitter while Tyler Nevin starts at first base Sunday.