Rocker will serve in a bulk-relief role for the Rangers during Monday's game against the Marlins, Kennedi Landry of MLB.com reports.
Rocker's best outing this season came as a bulk reliever May 19 in Colorado, when he struck out seven over 7.2 shutout innings. Tyler Alexander was the opener in that contest, and the Rangers will work with the same setup Monday as Alexander takes the ball first in the series lid-lifter.