A Bears defense in need of improvement will have to do it with rookie Jon Bostic filling in for injured D.J. Williams at middle linebacker for the remainder of the season.
"I've got to step up now," Bostic said. "I don't want any drop-off from D.J. to me."
The Bears' defense is 20th in yards per game (373), 12th in rushing yards (102.0 per game) and 23rd in passing yards (271.0). It will face a Washington Redskins offense that is fifth in the league with 399.2 total yards per game and 10th in rushing yards (128.0) and passing yards (271.2).
The 4-2 Bears are counting on reinforcements Sunday against the 1-4 Redskins at Fed-Ex Field. Pro Bowl cornerback Charles Tillman and nose tackle Stephen Paea both could be back.
Tillman missed the Week 6 victory over the New York Giants with a knee injury that kept him out of Monday's practice, but he's expected back after missing his first game since 2009.
Paea, who has been sidelined for two games with a toe injury, practiced Monday and is looking forward to returning. Before his injury, he had consistently graded the highest on a defensive line that has struggled most of the season and has lost Henry Melton and Nate Collins to season-ending knee injuries.
"I look around the inside, it's just me and Corey (Wootton) right now," Paea said. "We've got to step up. That means, if we have to play more snaps in there, we've got to. That's what coach tells us."
Injuries have forced defensive end Wootton inside to the 3-technique spot, where Melton made the Pro Bowl last season. Free agent Landon Cohen started at nose tackle vs. the Giants and the only backups inside were rookies Zach Minter and Christian Tupou, who got their first NFL snaps.
Bostic has a wealth of experience compared to the two rookie tackles. He started all four preseason games while Williams was out with a hamstring injury. But the second-round pick out of Florida had been limited to special teams until Williams suffered a season-ending chest injury in the third quarter Thursday night.
"He's in the next-man-up situation," coach Marc Trestman said. "He doesn't have the experience certainly that D.J. has, but he has speed and he's an explosive young man. It's just about working together with the guys and getting acclimated to the calls and the fits and things like that. I think we'll do fine."
Bostic says he has benefited from the experience in the linebackers' room, including 10-year veteran Williams, 11-year veteran Lance Briggs and eight-year veteran James Anderson.
"Lance has taught me a lot," Bostic said. "Some things he teaches me, he doesn't even know he teaches me. I watch those guys more than they think. I ask them a lot of questions."
Observation, asking questions, experience in the preseason, special-teams duties and his habit of taking copious notes, which he began while playing for Will Muschamp's Gators, all help Bostic prepare. And he has flashed enough potential for veteran teammates to welcome his contributions.
"We're going to miss D.J. a lot," cornerback Tim Jennings said. "He's played some good ball for us. But I'm excited about Bostic. He put on a show this preseason. I know a lot of guys are excited to see what he's going to be doing. This is just an opportunity for Bostic, to let everybody know he's here for a reason."
In his first professional game, the second-round pick intercepted a pass and returned it 51 yards for a touchdown. But Bostic knows, at this level, any urge to freelance must be weighed against being assignment sound.
"You've got to let the big plays come to you," he said. "You can't try to go out there and try to force a big play because that's when mistakes happen. (If) you jump out of your gap, and it's two people in one gap, it leaves a seam inside and causes a big play for the other team.
"It's really just going out there and just playing by our rules."
•Defensive end Tracy Robertson was signed to the practice squad. The 6-foot-4, 300-pound Baylor originally signed with the Houston Texans in 2012 as an undrafted free agent and also has spent time with the Lions, Patriots and Dolphins but has not appeared in a regular-season game.
There was an open spot on the practice squad after defensive tackle Christian Tupou was elevated to the 53-man roster last Wednesday.
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