The Cowboys were also without starting right tackle Zachary Crabtree on Saturday in their 44-31 upset loss to No. 16 TCU. Crabtree is still recovering from a toe injury suffered last weekend at Pittsburgh.
Crabtree, a preseason All-Big 12 selection, has 36 career starts and is the most experienced offensive lineman in the conference. Williams was in his second season as a starter.
The Cowboys are hopeful Crabtree will be able to return next weekend at Texas Tech. When he returns, they will have the option of moving Jenkins back to guard, where he had been listed as Williams' backup on the depth chart.