The number behind the starter can quickly become just as important, a lesson the Dallas Cowboys learned during the Tony Romo years and, more recently, during the Dak Prescott era. MORE: Updated list of Cowboys NFL Draft picks after free agency's first week While Dallas is not overly concerned about the position with Prescott returning from a season-ending hamstring injury,

Rush has become a well-known figure in Dallas over the last seven years, primarily serving as Dak Prescott’s backup for most of his career.

Rush had spent nearly his entire NFL career backing up Dak Prescott. Now he'll join an AFC contender and sit behind 2x-league MVP Lamar Jackson.