Dallas won't return to Sunday's game against Washington due to an ankle injury, Curtis Crabtree of Sports Radio 950 KJR Seattle reports.
It appears to be a serious injury as the 22-year-old was carted off the field, though the specifics of the issue remain unclear. Rashaad Penny was activated from the PUP list Saturday and will work as Seattle's No. 3 tailback with Dallas sidelined.