ORCHARD PARK, N.Y. — Buffalo’s Marcus Stroud has been ruled out because of a knee injury, meaning the NFL’s worst run defense could be without both starting defensive tackles against Jacksonville this weekend.

Kyle Williams has missed three games because of a knee injury, and was listed as questionable by interim head coach Perry Fewell on Friday. Williams has practiced sparingly this weekend.
The Bills (3-6) have only two other defensive tackles on their roster, reserves Spencer Johnson and John McCargo.
Their defense is allowing an NFL-worst 173 yards rushing this season. Buffalo prepares to face the run-happy Jaguars led by Maurice Jones-Drew, who’s tied for fourth in the league with 860 yards rushing and has scored seven of his 12 touchdowns in the past four games.
Stroud was hurt in a 41-17 loss at Tennessee last weekend, and has not practiced this week. Except to refer to Stroud as day to day, Fewell wouldn’t divulge the nature of the injury.
While strong safety Donte Whitner is set to return after missing three games with an ankle injury, the Bills banged-up defense could be down another regular with rookie safety Jairus Byrd listed as questionable because of a nagging groin injury. The second-round draft pick out of Oregon, Byrd has a league-leading eight interceptions to tie the Bills’ rookie single-season record. He also has a five-game interception streak.
Reserve cornerback Ashton Youboty was also ruled out after hurting his ankle last weekend.
Injured linebacker Kawika Mitchell made an appearance in the locker room Friday. Placed on injured reserve after hurting his right knee in a 6-3 loss to Cleveland on Oct. 11, Mitchell said he had successful surgery five weeks ago and should be ready to begin working out in March.