JACKSONVILLE, Fla. -- The Jacksonville Jaguars have one of the worst run defenses in the NFL. They’re hoping the addition of defensive tackle Marcell Dareus will help, and help enough for them to win the AFC South.

The Jaguars are next to last against the run (138.6 yards per game), and nobody allows more than their 5.2 yards per rush. The 6-foot-3, 331-pound Dareus gets headlines because of his prowess as an interior pass-rusher (35 sacks in six-plus seasons, including 7.5 in 2013 and 10.0 in 2014), but he’s one of the league’s better run-stuffing tackles.

Dareus is now the Jaguars’ biggest defensive lineman and he can play both nose tackle and 3-technique. The two-time Pro Bowler will likely move into the starting lineup ahead of nose tackle Abry Jones (6-foot-4, 318).

The Jaguars (4-3) opted to keep Jones over Roy Miller -- who is now with Kansas City, and he hasn’t played badly -- but Jacksonville doesn't have an experienced backup behind him. Dareus and Jones should give the Jaguars a good rotation at nose tackle.

Dareus has had more than his share of off-field issues -- he was benched for being late to a team meeting in 2013, was sent home from a preseason game this year for violating a team rule, was twice suspended for violating the NFL’s substance-abuse policy, and he’s had two offseason arrests -- but the Jaguars believe the help the Alabama product can bring the run defense is worth the risk.

It’s clear the Jaguars needed to do something. In their four victories, they’ve allowed only 98.3 yards per game rushing. However, they’ve given up 192.3 in their three losses. Defensive coordinator Todd Wash and several players have said a lack of gap discipline, over-pursuit and backside cutbacks are the biggest problems. Those are discipline issues and can be corrected, but it is troubling that it seems to occur each week.

The Jaguars’ chances of winning the division and making the playoffs rest on the defense. The pass defense has been stellar -- Jacksonville entered Week 8 ranked first in the NFL in sacks (33), interceptions (10) and turnovers (16) -- and cornerbacks Jalen Ramsey and A.J. Bouye have established themselves as one of the best cornerback duos in the NFL.

The addition of safety Barry Church also was one of the team’s best offseason moves, shoring up a weak spot in replacing Johnathan Cyprien.

The one glaring defensive weakness has been stopping the run. The Jaguars are gambling that Dareus is the fix they need.