The Jaguars (2-11) have given up an average of 159 yards rushing and 4.77 yards a carry since placing their defensive leader on injured reserve in October with a torn pectoral muscle.
They were gouged on the ground in a 27-13 loss to Houston on Sunday, allowing Arian Foster to carry 24 times for 127 yards and a touchdown. The Texans finished with 42 carries for 173 yards, averaging 4.1 yards an attempt.
''You don't like to give up that many yards rushing,'' coach Gus Bradley said Monday. ''Some of it is scheme-based, what are we willing to give to make sure we take care of other things? ... When you run the ball 42 times, there's going to be a couple of explosives in there.''
J.T. Thomas moved inside to replace Posluszny, and Bradley said he played well. But Jacksonville's best linebacker combination was with Posluszny in the middle, Thomas outside and rookie Telvin Smith coming in on passing downs.
''We've been a lot better in certain aspects of the run game, but we've given up some big numbers on certain plays,'' Thomas said. ''That has been our weak spot. We need to do what we have to do to cut down on those long runs, turn some of those 40-, 50-, 60-yard runs into 10- or 20-yard runs, try to help ourselves out a little bit more.
''I think everyone is doing everything in their power to make sure we get better in that aspect of the run game.''
Indeed, the Jaguars have given up too many long runs.
Foster had a 51-yard gain in the first half Sunday that led to a field goal. Dallas' Joseph Randle (40 yarder) Cincinnati's Jeremy Hill (60 yarder) and Miami's Lamar Miller (30 yarder) also gashed Jacksonville for big gains on the ground in recent weeks.
No one knows for sure if Posluszny would make a difference, but the numbers show the Jaguars better against the run with him on the field.
In the seven games Posluszny played, the Jaguars allowed 110 yards a game on the ground and 3.77 yards a carry. He tore a pectoral muscle against Cleveland on Oct. 19 and had season-ending surgery.
''Poz is great, but I just can't see (his absence) as being the reason we've given that much up,'' defensive tackle Sen'Derrick Marks said. ''It all comes down to everybody being where they're supposed to be. I wouldn't say it's just because of Poz. He's a veteran. He's been doing this an awfully long time.
''With older guys, they may not be as athletic, but they know where to be and when to be there. We have guys in the right place, but they may over-run the play or might be a step too late. I think that just comes with experience. With Poz, it's a matter he knows exactly where he's supposed to be.''
The Jaguars hope to be better against the run Sunday at Baltimore, which ranks fifth in the league with 135.7 yards rushing a game. And running back Justin Forsett, who spent last season with Jacksonville, surely will have extra motivation given the Jaguars released him after one injury-filled season.
Thomas said teams are running more on Jacksonville because of the team's pass defense. The Jaguars rank third in the league with 39 sacks, a bright spot for a unit that ranks 27th in the NFL in yards and 28th in rushing.
''It's a matter of give and take in a game,'' Thomas said. ''Do you give up something to concentrate on another aspect? We've been facing teams that want to run the ball, kind of protect their quarterback. They know we're very good in the pass game, that we create turnovers with our front.
''Guys want to stay away from trouble. We look forward to these next three opportunities to put some good stuff out there on film as a defense, build our foundation and keep moving forward.''
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