The Seahawks signed center Patrick Lewis on Wednesday as insurance in case starter Max Unger cannot play Sunday vs. Dallas.

Unger suffered a foot injury — coach Pete Carroll called it a strain — against Washington on Monday and apparently is questionable for Sunday’s game. Unger reportedly was wearing a walking boot after the game.

With Lemuel Jeanpierre on injured reserve, Stephen Schilling would start at center if Unger cannot play.

The Seahawks have been light on the line all season, and Schilling has been their only real interior reserve. Alvin Bailey can play guard in a pinch, but he is dealing with a quadriceps injury that kept him out of the game in Washington.

Lewis was picked up by Seattle late in the preseason and waived on final cuts. He had been on Cleveland’s practice squad.

To make room, the Hawks waived cornerback Josh Thomas, who was signed Sept. 8 when the Hawks lost Jeremy Lane to a groin injury. The Hawks are now back to three cornerbacks, not counting the versatile (but emergency corner only) DeShawn Shead.