Martinez (elbow) will start at DH for Triple-A Toledo on Friday, Matthew B. Mowery of The Oakland Press reports.
Martinez has gone 4-for-10 in his first two rehab assignment games and will be back out there in the DH role Friday against Triple-A Gwinnett. He's yet to advance to playing in the outfield during an outing but that will likely occur in the coming days. Pending any setbacks, the 28-year-old is still projecting to return to the Tigers in early August.