FLOWERY BRANCH, Ga. -- There was so much optimism coming into the season about the direction of the Atlanta Falcons’ defense and how it might develop into one of the league's top units under fiery defensive coordinator Marquand Manuel.

Then attrition hit.

First, Pro Bowl strong safety Keanu Neal was lost to a season-ending left ACL tear. Then Pro Bowl middle linebacker Deion Jones was placed on injured reserve and will be out until at least Nov. 18 following right foot surgery.

After watching defensive ends Takkarist McKinley and Derrick Shelby suffer groin injuries -- McKinley apparently is progressing faster than Shelby -- the Falcons then lost arguably their most important defensive player when free safety Ricardo Allen went down this past Sunday with a season-ending torn Achilles tendon. Allen was the brains of the operation with his ability to get everybody lined up correctly and call out the opposition's plays before they happened.

"Definitely tough losses," nose tackle Grady Jarrett said of Allen and the others. "We care about guys as humans. In this profession, you get hurt. It's unfortunate. We just have to rally together."

Jarrett, another of those high-impact defenders the Falcons can ill-afford to lose, knows what's at stake now. His team is 1-2 overall and decimated by injuries heading into Sunday's 1 p.m. ET matchup with the 2-1 Cincinnati Bengals. Sure, the offense is capable of carrying the extra weight and scoring 30 points per game. Quarterback Matt Ryan has one of the best receiving corps around with Julio Jones, rookie Calvin Ridley, and Mohamed Sanu, plus talented running backs in Devonta Freeman -- once Freeman returns from a right knee contusion -- Tevin Coleman, and rookie Ito Smith. And yes, 43-year-old Matt Bryant still has a powerful enough leg to kick a game-winner on any given Sunday -- or Monday or Thursday.

But the defense has to be able to stop someone.

"Yeah, we've got to stand up," Jarrett said, understanding this could be a crucial stretch in the grand scheme of the season. "You don't ever want to fall behind too far. We lost two really, really close games. We could easily be sitting here 3-0, but that's not the case. We just have to get back to work."

Fortunately for the Falcons, the previously undefeated Tampa Bay Buccaneers fell to the Pittsburgh Steelers on Monday night, 30-27, so the division teams above them are all 2-1. The next three Atlanta opponents -- the Bengals (2-1), Steelers (1-1-1), and Buccaneers (2-1) -- feature dangerous offensive threats such as A.J. Green, Ben Roethlisberger, Antonio Brown, Mike Evans, DeSean Jackson, O.J. Howard, Andy Dalton, Ryan Fitzpatrick, AFC rushing leader James Conner and even new stiff-arm king Vance McDonald. And all three opponents rank in the top seven in scoring offense with Tampa Bay third at 34 points per game, Cincinnati sixth (29.7), and Pittsburgh seventh (29.3).

The Falcons are ninth, by the way, scoring 26.7 points per game, but their scoring defense ranks 25th, surrendering 28.3 points per contest. Atlanta's defense also ranks 31st in yards per rush (5.2), first downs per game (25.7) and third-down conversion rate (48.8 percent).

Falcons coach Dan Quinn expressed a firm belief in his defense regardless of the injuries. In fact, Quinn appears content with the safety situation despite losing his top two (Neal and Allen). Sure, talented Damontae Kazee stepping in for Allen might not hurt the Falcons so much, provided Kazee has learned from being ejected for a hit on Carolina quarterback Cam Newton. But the Falcons are unlikely to find anyone close to Neal's caliber out of strong safety candidates that include Brian Poole, Jordan Richards, Kemal Ishmael and Keith Tandy. Neal's hard-hitting, in-the-box style made opponents think twice about coming his direction.

Quinn indicated the Falcons have no immediate intentions to sign talented free-agent safety Eric Reid, who last played in a similar system with the San Francisco 49ers. Quinn said it has nothing to do with Reid taking a knee during the national anthem in supporting former teammate Colin Kaepernick's fight against social injustice. Reid reportedly sought a multi-year contract before not re-signing with the 49ers.

Quinn did say the Falcons plan to work out a group of safeties for depth, not a starting role. No matter who the Falcons bring in at safety or any other defensive position, the key to improvement starts up front. Consistent pressure has been lacking. The Falcons rank 30th in sacks per pass attempt and their five total sacks ranks 28th overall.

"The three-deep system that we play, obviously putting pressure on the quarterback is a big part of that," Quinn said. "When you play zone defense, if you're not going to get the quarterback to move, it's going to get harder. ... So usually for us, it's the amount of times we can hit the quarterback, make [him] move, that makes us most effective."

The Falcons need 2016 sack champ Vic Beasley Jr. to get into a rhythm after collecting his first sack last Sunday against Drew Brees. They need McKinley back healthy, because he has a nasty edge to him. And they need Jarrett to keep being his typical disruptive self.

Consistent tackling would help, too, after the Falcons missed at least 12 tackles against New Orleans, including at least nine by the defensive backs.

"I expect some of those missed tackles in the first game, I do not expect those in the third game," Quinn said. "Good news, a number of these are totally correctable with our technique ... When we shine a light on something, we usually get the result we're looking for."

We'll see if that holds true for the defense this week, as a whole.