Hankins (ankle) has been ruled out for Sunday's contest against the Dolphins, Bobby Belt of 105.3 The Fan reports.
Hankins missed all three practice sessions for the second straight week as he deals with a high-ankle sprain he sustained in Week 14 against the Eagles. Mazi Smith got extended snaps at defensive tackle alongside starter Osa Odighizuwa in the Cowboys' Week 15 loss to the Bills, and the former figures to reprise that role for Sunday's game.