Mathis (ankle) has been ruled out for the rest of Sunday's preseason game against Arizona, Chris Tomasson of The Denver Gazette reports.
Mathis' status for the Broncos' regular-season opener against the Seahawks is also up in the air after he was carted off the field following his injury Sunday. If he weren't able to suit up, Riley Moss would be the likely candidate to serve as Denver's second starting corner opposite Patrick Surtain.