Dallas Cowboys left tackle Tyron Smith has been ruled out for Sunday's game at the Miami Dolphins because of a back injury.
A two-time All-Pro and eight-time Pro Bowl selection, Smith was listed as doubtful before he was downgraded Saturday after not practicing this week.
Smith, who turned 33 on Dec. 12, will miss his fourth game this season. The Cowboys said that Chuma Edoga will start in his place, while starting right guard Zack Martin (quadriceps) remains listed as questionable.
Also Saturday, the Cowboys (10-4) elevated running back Malik Davis and nose tackle Carl Davis from the practice squad to the active roster.
Dallas ruled out defensive tackle Johnathan Hankins (knee, ankle) on Friday for the game versus the Dolphins (10-4).