Marks (knee) wasn't spotted during the portion of Thursday's practice session open to reporters, Aaron Wilson of KPRC 2 Houston reports.
After being deemed a limited participant Wednesday, Marks' apparent absence a day later is noteworthy, though it's possible it's maintenance-related. Thursday's upcoming injury report will provide added context on that front, as well as the participation level of fellow RB David Montgomery (groin), who was on the field Thursday.