If Bears wide receiver Brandon Marshall were running an offense, he wouldn’t challenge linebacker Lance Briggs — regardless of how much time Briggs has missed.

Why?

“His history says enough,” Marshall said.

On Sunday, we should learn if Eagles coach Chip Kelly feels the same way. After injuring his left shoulder Oct. 20 against the Redskins and missing seven games, Briggs is on track to return in Philadelphia. He practiced with the Bears’ first-team defense on a limited basis Wednesday, and coach Marc Trestman continues to say he’s optimistic he’ll play Sunday night.

With their uptempo approach and league-best running game led by LeSean McCoy, the Eagles might not be an ideal opponent for any linebacker in his first game in more than two months. But for a beleaguered defense that actually has gained some momentum the last couple of weeks — especially after containing Dez Bryant, Josh Gordon and Jordan Cameron — getting Briggs back could be a significant boost at a significant time.

Briggs, who was originally on a six-week timetable, declined to speak to reporters, promising to take the podium Thursday. But the buzz of his return couldn’t be contained at Halas Hall. Everything points to a return.

“It would be a huge help for our defense, getting one of our leaders back,” linebacker James Anderson said.

“Before he got hurt, he was having an incredible season, so it will be great to have a guy like him, a perennial Pro Bowler, back,” defensive lineman Corey Wootton said.

“He definitely brings an energy and a feeling back to the defense that might have been missing,” safety Chris Conte said. “It’s a good time to have him back and make this [playoff] push.”

The Bears’ injury-plagued defense had issues even when Briggs was healthy. But since he left in the third quarter against the Redskins, the Bears became the worst run defense in the league, allowing an average of 187.6 yards in the seven full games he missed. Those problems led to Briggs talking about the defense’s heart on his weekly Comcast SportsNet show.

Seeing film of the Bears’ problems has made McCoy giddy.

“Seeing things like that and missed tackles and guys out of line, out of place, that kind of makes a running back happy,” McCoy said. “And seeing teams gash ’em, automatically that light bulb lights up in your head like, ‘Wow, we can get the running game going.’ ”

The Bears have high hopes for rookie linebackers Jon Bostic and Khaseem Greene, but their learning curve was accelerated with Briggs and D.J. Williams injured. Briggs turned into another coach for Bostic and Greene.

“It’s like he’s been out there with us every step of the way,” Bostic said. “He’s standing right behind Khaseem, me and James, saying, ‘Hey, you should fit here, fit here. See this faster. Get downhill here.’ ”

But nothing replaces Briggs actually being there every step of the way on the field. He turned out to be a much bigger loss for the Bears than quarterback Jay Cutler.

Briggs had 75 tackles, nine tackles for loss, two sacks, five pass breakups and two forced fumbles before his injury.

If Briggs returns against the Eagles, his conditioning will be tested against their high-paced offense.

“Certainly, he hasn’t played football in a long time,” Trestman said. “[But] Lance is a unique athlete. It would certainly be exciting to see him out on the field.”

Email: ajahns@suntimes.com

Twitter: @adamjahns