Ricardo Allen was as emotional as anyone after he saw teammate Keanu Neal suffer yet another season-ending injury on Sunday, but the Atlanta Falcons free safety has learned not to dwell on the uncontrollable.

Of course, Allen knows that Neal’s presence will be missed on defense for the remainder of the season following an Achilles tendon tear, which typically requires eight months for recovery. But Allen, who suffered a season-ending Achilles tear last season, isn’t about to let his fellow defenders use Neal’s injury as an excuse.

"My message to the defense? Do your job. That’s all," said Allen, a team captain. "Whatever your job entitles, do that. Do it as hard as you can for your brothers. That’s it. We’re not asking nobody to be Superman. Just be who you are and what you’re supposed to be for this team.

"Yeah, we understand it’s going to be 'mess-ups' here and there, but you’ve got to do it for everybody around you. If you do your job and they beat us doing your job, they deserve it. But if they beat us and we’re not doing what we’re supposed to, that’s on us."

The 1-2 Falcons have to do a much better job on defense now without Neal roaming as the enforcer. The 27-24 loss to the undermanned Indianapolis Colts exposed some defensive flaws that could doom the Falcons if they are not corrected. Players were caught looking in the backfield, as Colts coach Frank Reich masterfully designed misdirection and play-action plays. If the Falcons were fooled by Andrew Luck's replacement, Jacoby Brissett, just imagine what type of issues could lie ahead with Deshaun Watson, Russell Wilson and Drew Brees in the next six games. That's not to mention the variety of looks the Falcons could see from offensive gurus Sean McVay and Kyle Shanahan later in the season.

The Falcons continue to have penalty issues, which point to a lack of discipline. Four of the 16 penalties they drew against the Colts came against the defense on third down, allowing the Colts to pick up first downs. The Colts had seven first downs by penalty in the game. It makes you wonder if coach Dan Quinn should take sterner action against repeat violators.

One of those defensive penalties was too many men on the field, as the Falcons were caught switching personnel, and defensive tackle Grady Jarrett couldn’t get out of the game. Quinn, as the defensive coordinator, didn’t feel good about the lack of communication but vowed to get the penalty issues fixed this week while having officials out for practice. The Falcons have done that regularly, but Quinn emphasized it this week in preparation for Sunday’s matchup with Tennessee.

The Falcons are tied for 29th in the league in third-down defense, allowing opponents to convert 52.8% of the time. They are giving up 21.7 first downs per game, which is tied for 22nd. Their minus-five point differential, with the defense yielding 25 points per game and the offense scoring 20 points per game, ranks 22nd.

"I think it’s about the small details on defense," cornerback Desmond Trufant said. "I felt like [against the Colts], it was more we were inflicting damage on ourselves than them beating us. I mean, they made some plays, but I think we’ve got to start with doing our job first, getting in position. ... We’ve got to make sure we’re doing what we’re supposed to do."

This week’s task likely means preparing for what Titans quarterback Marcus Mariota is capable of accomplishing as a dual-threat quarterback and the power Derrick Henry brings in the running game. At the same time, the Falcons can’t be fooled into thinking it’s all about stopping the run because Mariota might try to go downfield to wide receiver Corey Davis or someone else.

More thing anything, the Falcons can’t sulk about Neal not being in the lineup. Quinn talked about Kemal Ishmael stepping in to play some strong safety. But filling in for Neal might be by committee, with Quinn looking at all options. Safety Jamal Carter was elevated from the practice squad for depth. Nickelback Damontae Kazee played free safety last season. But it will be difficult for anyone to mirror Neal’s impact when healthy.

"Just the way that he brings the pain, man, and the way that people have to account for No. 22," Allen said. "When they know he’s coming, people pull hands down. Tipped balls happen a little bit more.

"That’s why I think we ended up winning that game on fourth down against the Eagles -- because they saw 22 coming and pulled that ball back. You understand when 22 is out there, he’s trying to get that ball. And if he’s not trying to get that ball, he’s trying to get you. He’s an enforcer, and we’re going to miss that. It’s a physical presence that’s hard to match when you take a guy like him off the field."