The White Sox optioned Sandlin to Triple-A Charlotte on Tuesday.
Sandlin was terrific in his major-league debut last month versus the Twins with six innings of one-run ball, but he yielded 11 runs over 7.1 innings in two appearances since then. His turn as a starting pitcher/bulk reliever will come up this weekend against the Dodgers, and the White Sox have not announced how they plan to fill that vacancy.