FRISCO, Texas -- Pro Bowl left tackle Tyron Smith was unable to finish Friday’s practice because of a tight back, but the Dallas Cowboys expect him to be able to play Sunday against the Chicago Bears.

Officially, Smith, who has missed just one game in his career, is listed as questionable. Right tackle Doug Free went through a full practice Friday with a quadriceps strain that left him limited in practice on Wednesday and Thursday.

Chaz Green and Zack Martin likely would be the tackles if Free and Smith take a downturn, with Ronald Leary moving in at right guard.

“We’re ready if something happens there,” executive vice president Stephen Jones said, “but we expect them to play.”

Cornerback Orlando Scandrick did not practice for the third straight day because of two hamstring strains. He also is listed as questionable, but the Cowboys likely will go all the way until 90 minutes before kickoff prior to making a decision.

“He’s been working through this and I admire him because he’s definitely got something going on there, but we want to be careful,” Jones said. “At the same time, he’s a competitor and wants to be out there. We’ll make that decision at game time.”

Defensive end Jack Crawford (shoulder) is questionable and linebacker Mark Nzeocha (Achilles) is doubtful. Quarterback Tony Romo (back) and defensive end Charles Tapper (back) have been ruled out.