Odor isn't starting Thursday against the White Sox due to back soreness, Roch Kubatko of MASNSports.com reports.
Odor is out of the lineup for a second consecutive game Thursday, and he apparently sustained his back injury on a swing while serving as a pinch hitter Wednesday against the Nationals. However, it's possible he'll be available off the bench Thursday, so he should tentatively be considered day-to-day.