The White Sox optioned Martin to Triple-A Charlotte on Sunday.
Martin's demotion likely signals that the White Sox anticipate Michael Kopech (knee) will be ready to return from the 15-day injured list Wednesday when first eligible to reclaim his spot in the rotation. While making the last two turns through the rotation as a replacement for Kopech -- once as a starter and once as a bulk reliever -- Martin went 0-1 with a 3.38 ERA, 1.50 WHIP and four strikeouts in eight innings.