One of the most referenced concerns for the Cowboys heading into the 2021 season is the run defense. The Dallas defense was poor all around last year, but the run defense was especially bad. The team was ranked as the second-worst in the league after giving up 158 yards per game on the season. The Cleveland Browns actually put up over 300 yards rushing on Dallas, an astronomical number.
Part of the problem was the change in scheme and coaching. For a good part of the season nothing went right on defense as players were slow to react to plays and were often caught out of position.