IRVING, Texas — The Dallas Cowboys have signed first-round pick Travis Frederick, the last of their unsigned draft choices.

The center from Wisconsin signed a four-year deal with a club option for a fifth on Tuesday. The Cowboys now have all seven draft picks under contract. Training camp starts July 21.

Frederick was the first-team center throughout offseason workouts, but is expected to battle fourth-year pro Phil Costa for the starting job in training camp. Frederick also will get work at guard, his previous position in college.

The Cowboys traded down 13 spots and picked Frederick at No. 31. They said the offensive line was a top priority after one of the worst rushing seasons in club history.