With Will Witherspoon, Dunbar's replacement, nursing an injured hamstring, there's a realistic chance that Dunbar will plug right back into the starting lineup after re-signing with the team Tuesday afternoon.
Dunbar's return should give the defense a much-needed boost in terms of intangibles like intensity and toughness.
"He's an integral part of this defense, what we did last year and what we hope to do the rest of the year," end Chris Long said. "He's a spark plug for us, he brings energy, he brings passion for the game and not just that, he's a damn good player. When you get a damn good football player back on a team where we haven't played up to our standards, that can't hurt at all."
Getting Dunbar back will certainly do plenty for the Rams in terms of leadership and camaraderie in the locker room. The fiery Dunbar has close relationships with team leaders like Long and middle linebacker James Laurinaitis and the apparent respect of his younger teammates.
There were no signs of resentment left over from Dunbar's four-game suspension for violating the league's policy on performance enhancing substances. Upon his return to the locker room Tuesday, he was greeted with open arms and man hugs galore.
"It's been great to come back and just see smiles on people's faces," Dunbar said. "It felt good to know I'm back around some of the guys and they wanted me here as much as I wanted to be here."
Dunbar provides plenty of those intangibles on the field, too. Laurinaitis cites Dunbar as a helping hand in terms of making sure the calls are correct and the defense is lined up right.
"I love playing next to Jo-Lonn," Laurinaitis said. "He is a fiery, passionate, angry football player ... It's good to have that extra edge on the defense and another guy that helps keep guys accountable. He is very vocal and the more of those kinds of players you can have on defense, the better."
As for more tangible (and important) things such as tackles, sacks and interceptions, Dunbar can certainly be helpful, as his 2012 statistics would attest. He posted 115 tackles, 4.5 sacks and a pair of interceptions last year.
But Dunbar's addition isn't going to be some sort of panacea to the league's 23rd-ranked defense.
Dunbar is returning to a role different than the one he had in 2012 when he was on the field for all three downs alongside Laurinaitis. Even before Dunbar's release Sept. 3, that role had been cast with rookie Alec Ogletree next to Laurinaitis.
Witherspoon played 102 snaps out of a possible 255 in the first four weeks and Ray Ray Armstrong played an additional 15 in his place last week, meaning the Rams have had a third linebacker on the field almost 46 percent of the time.
If nothing else, Dunbar's presence should provide an immediate boost to the team's struggling run defense for the downs he's on the field. Dallas and San Francisco have gashed the Rams to the tune of 206 rushing yards per game over the past two weeks.
Dunbar is a physical presence in the run game and his 13 tackles for loss in 2012 should serve as a reminder of where he's at his best: defending the run. Pro Football Focus graded Dunbar as the team's second-best run defender last year with an 8.6 cumulative score, trailing only defensive end William Hayes.
Although Dunbar admits that his suspension and subsequent release helped him take stock of what's really important, he said nothing would change in terms of that approach.
"I'm just going to play the way Jo-Lonn plays which is with fire, hair on fire and just get after some guys and just be Jo-Lonn," Dunbar said. "That's the only thing I can be."
For a defense struggling to find an identity in the first four weeks, every little bit counts.