The Achilles’ heel for the Eagles defense has been third-down lapses. Can Sean Desai solve it?

Sean Desai is searching for ways to make his defense more opportunistic.

The Eagles defensive coordinator’s group has struggled in myriad ways over the last month, but few areas are as glaring as the inability for the defense to capitalize on favorable third-down situations.

“We have been inopportune,” Desai said Wednesday. “We have not been able to get off the field when we need to get off the field. Yeah, in third down and situational football, we’ve got to be better, third down, red zone. Those have been our bugaboos. Not going to lie to you. That’s been our Achilles’ heel right now.”

Desai’s comments come after a nightmarish stretch for the defense, which has resulted in the team ranking last in the NFL with a 48.1% conversion rate in third-downs allowed and a 5.1% third-down sack rate. What’s even more concerning is the Eagles allowing a 61% conversion rate in their last three games while giving up 451 yards and 36 points per game.

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The inability to get teams off the field is the reason for the staggering yardage and point totals, something Desai said will require him to identify answers for the struggling defense more quickly when things aren’t going well in games.

“It’s been a few different areas and kind of been different each game or even each situation,” Desai said. “Obviously, it always starts with the play call. You can always reflect and put them in a better situation after you see the play, what the route is, and how you want to match that route differently based on the coverages in the system we’ve got up that week.”

After the Eagles’ 33-13 loss to the Dallas Cowboys, several players said Desai made an effort to “simplify” things, especially for the secondary. Even though the Eagles have mostly veterans on the back end, it’s fair to point out that starters Kevin Byard and Bradley Roby each joined the team in midseason.

The simplified approach produced similar results to the week before when the Eagles gave up 42 points to the San Francisco 49ers. Going into halftime of the Cowboys game, the Eagles had given up 10 consecutive scoring drives excluding one Niners drive to run out the clock at the end of that game.

“The last two weeks is not our standard, and we accept that and know that,” Desai said. “We’re going to lean back into what we really believe in ourselves and our standard and we’ve got to go back and achieve that from a coaching and a player standpoint.”

When looking at the Eagles’ third-down woes, it’s only fair to acknowledge the external circumstances beyond Desai’s play-calling and certain personnel shortcomings. The Eagles’ undermanned linebacking corps struggled mightily against the 49ers and the defensive front didn’t have a significant impact for most of the game against the Cowboys.

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After the Eagles led the NFL with 70 sacks last season, the team’s heavy investment in its defensive front hasn’t led to enough pivotal sacks in the last few games. The defense ranks 13th in sacks and ninth in pressure rate this season, but most of the production has come on early downs. In the last three games, the Eagles have managed just three third-downs sacks.

Part of that insufficient sack production is due to coverage breakdowns on the back end of the Eagles defense. According to Pro Football Focus, Cowboys quarterback Dak Prescott went 8-for-12 while averaging 10.2 yards per completion when pressured by the Eagles in their loss at AT&T Stadium.

“That’s a function of rush and coverage working together with the play call,” Desai said regarding the lack of third-down sacks. “You’ve got to get the quarterbacks off the spot, buy some time in the coverage, and then we’ve got to win when we get some matchups up front consistently. We have to keep working to improve there.”

With four games left to play, the defense will need to quickly seize the opportunity still in front of it. The Eagles still control their own destiny in the NFC East with two division games against the Giants upcoming, but a loss on Monday to the Seattle Seahawks would leave them requiring help in both the division race as well as the hunt for the No. 1 seed and the first-round bye week that comes with it.

“The cool thing is we have every goal still to be reached ahead of us,” Desai said. “We have to really lean into that. We learn from our past. The good and the bad in the past. Then we have to move forward and own all of our responsibilities and roles and go master them.”