The Eagles have long undervalued linebackers. They would say they’ve invested the appropriate amount, especially when compared to other positions.

For years, the NFL has been trending in this direction, but the Eagles have often been among the teams that have spent the least on linebackers. This season, for instance, only 4.4% of their salary cap has been allocated to the position, and only the Cincinnati Bengals and Cleveland Browns have spent less.

Considering how the Eagles’ linebackers have performed through six games, it may be tempting to say, “You get what you pay for.” But the team has previously found ways to be successful without breaking the bank on the position.

Most of those defenses, though, were schemed to attack. Good offensive coordinators and quarterbacks still found ways to exploit the Eagles’ linebackers, but the systems of Jim Johnson, Sean McDermott, and Jim Schwartz often compensated for what their units lacked at the second level.

Jonathan Gannon’s system, at least thus far, has been considerably more passive. The new defensive coordinator has employed a zone-heavy scheme that is designed to limit explosive plays and accept some bend as long as there isn’t substantial breakage.

Gannon’s scheme has allowed for flexibility. Two weeks ago against the Carolina Panthers, he had cornerback Darius Slay follow receiver DJ Moore for most of the game. But the Eagles were still, by and large, in zone coverage with two deep safeties.

It worked well vs. Carolina’s Sam Darnold. But the consequences were unfavorable against better quarterbacks with the Dallas Cowboys, Kansas City Chiefs, and Tampa Bay Buccaneers. There were a myriad of reasons for the defensive breakdowns in those games, but Eagles linebackers couldn’t sustain the pressures placed on them by Gannon’s soft zones.

» READ MORE: Follow the Eagles-Raiders game as it happens on GameDay Central, with in-game comments from The Inquirer’s writers, photos and more

While it’s fair to surmise that Dak Prescott, Patrick Mahomes, and Tom Brady may have had similar success against a different tactic, each team would score a touchdown on its opening drive and at least 20 points by halftime.

The Eagles failed to force a single field goal in the first 30 minutes as the three teams collectively scored touchdowns on nine of 15 possessions, minus two run-out-the-clock possessions before the half. They strung together drives by being successful on the ground on first and second downs, and by executing their short passing concepts.

Gannon coerced the offenses to run early, a strategy that can be effective against explosive offenses with elite quarterbacks.

“To me, the ball travels faster in the air than it does on the ground,” Gannon said Tuesday. “Now saying that, you have to be good on first and second down.”

The Eagles, of course, were not good enough on early downs. Some of that fell on a defensive line that has struggled to adapt to multiple fronts. And some of that fell on the light boxes. But a lot has been on the linebackers who weren’t able to shoulder the additional weight from Gannon’s scheme.

“What we’re asking our guys to do might be a little bit different [than previously], or the coverages or the run fits or whatever that is,” Gannon conceded. “It is a new system.”

Alex Singleton, Eric Wilson, T.J. Edwards, and Davion Taylor have all had issues against both the run and pass. It’s one reason Gannon hasn’t settled on using just two linebackers in base and nickel packages.

“It always comes down to: Can you afford to take a guy off the field or not? If you can’t, then you leave him out there,” Gannon said. “But if you have a bunch of different guys that can play winning football within their role, let’s play them.”

Gannon was being generous with his latter comment, but it’s not as if the first three haven’t previously had a modicum of consistency. But his schemes place an emphasis on the linebackers while the Eagles did little to upgrade the position in the offseason.

In base, Gannon has utilized a 3-4 front. The last time the Eagles employed a similar front was with former coach Chip Kelly when DeMeco Ryans, Mychal Kendricks, and Jordan Hicks were his primary inside linebackers. Ample investment was made in each.

But general manager Howie Roseman added only Wilson, who signed a one-year contract, this offseason. Singleton came via the Canadian Football League, Edwards was undrafted, and Taylor was selected in the third round a year ago. (Shaun Bradley, the last of the group, was drafted in the sixth round in 2020.)

They have all had their ups and downs stopping the run, whether in filling gaps or fighting off blocks. But covering has been especially difficult because Gannon’s soft zones have asked the linebackers to account for more space.

Safeties Rodney McLeod and Anthony Harris have been rendered almost useless with both often 15-20 yards off the ball. Outside cornerbacks Slay and Steven Nelson hardly press and have played zone more than any starting pair in the NFL, per Pro Football Focus.

Slay is the fifth highest-paid cornerback in the NFL and he’s played man defense — his specialty — on only 8.4% of cover snaps.

If there were a foolproof defense, every team would use it. Gannon talked up versatility and diversity in scheme before the season, and yet no other defense has been in zone as often or blitzed as little as the Eagles.

The recent mini-bye allowed the 2-4 Eagles to step back and reassess their systems. Gannon spoke about having more of a “blend” in his game planning and play-calling.

“When I’m aggressive and I call it aggressively, our guys perform,” he said, adding: “So, that was part of the reflection for myself, is, ‘Hey, let’s maybe call the game a little more aggressively.’”

Schwartz didn’t blitz a lot, but his scheme was built around a penetrating D-line. He often had a safety in the box, and over time increased his usage of dime personnel partly to compensate for the deficiency in three-down linebackers.

Aside from one pivotal late third down against the Bucs — that they converted — Gannon hasn’t used dime. Zone-heavy schemes don’t necessarily need six defensive backs, but teams that employ that defense often devote resources to getting linebackers (e.g. Tampa).

There has obviously been a feeling-out process. The Eagles had a difficult six-game start. The schedule gets easier in the next five games, and considerably so in the final six. Gannon’s scheme may naturally become more aggressive against lesser offenses and quarterbacks.

But he has core tenets to his defense that would clearly benefit from having better linebackers. Here’s a closer look at some of the issues, focusing specifically on the Bucs game:

Attacking the linebackers

Tampa went after the Eagles’ linebackers, specifically Davion Taylor on its opening drive. The Bucs often used pre-snap motion to reveal zone or man coverage. On this first-down pass, the Eagles were in a quarters zone.

Taylor [No. 52] was in a tough spot. He bit on the play-action, but he was also responsible for the running back in the flat, which allowed Brady an unobstructed throwing lane.

Slay’s [No. 2] technique wasn’t sound, though, and receiver Mike Evans [No. 13] had plenty of space with Chris Godwin’s [No. 14] deep over route pulling the safeties.

A few plays later down by the goal, the Bucs went back at the linebackers. They had their jumbo package on the field, which kept the Eagles in base. They used play-action again to move the linebackers and sneaked tight end O.J. Howard [No. 80] across the formation.

Taylor was fooled by the misdirection, and edge rusher Ryan Kerrigan [No. 90] was late to react to a well-executed play.

The former earned his first career start last week and played the most snaps of his career. Gannon was asked how much patience he would have with Taylor having to learn on the fly.

“My expectation is everyone that goes out there plays winning football, and the patience level comes with we’ve got to make sure we’re not making the same mistakes over and over and over,” he said.

Playing soft

On the next series, the Eagles got what they wanted on first down: Tampa to run. And they executed with sound team defense that forced running back Leonard Fournette [No. 7] outside for no gain.

On second-and-10, the Eagles’ shell forced Brady to check down. An immediate stop by Singleton [No. 49] would have had Tampa in an acceptable third-and-5. But Fournette ran over the linebacker — he arguably used the crown of his helmet — and gained nine yards.

Stopping any offense on third-and-1 is a tough request. But the Eagles’ outside cornerbacks lined up way off receivers and well beyond the sticks. Nelson [No. 3] had no chance vs. a Godwin quick out that netted Tampa eight yards.

The Eagles’ pre-snap disguises weren’t effective early on. They often had Harris [No. 28] — and then his replacement Marcus Epps [No. 22] — drop into a shell at the snap. It’s unclear if the Bucs had recognized that McLeod was often the deep stationary safety, but this Fournette rush went to his side when he was 20 yards off at the snap.

It didn’t help that Taylor bounced off the tailback.

Forcing the run

The Bucs reached the end zone on their first two possessions, but Gannon’s defense settled down. Tampa played into their trap and ran here, for instance, on second-and-4.

The Eagles forced two punts on the next two series and had an Epps interception — that came off a Singleton pass breakup — reversed by replay. But on Tampa’s fifth possession, the defense cracked again.

Brady found tight end Cameron Brate [No. 84] over the middle on second-and-10, and Taylor was late to react.

Missed tackles

Brady was content with taking the short stuff, especially when the Eagles failed to wrap up, as Taylor did here.

Singleton missed four tackles on his own. He had some positive moments, as did Taylor, but they couldn’t hold up against the Bucs attack.

Facing the best

They weren’t alone. The entire defense struggled against perhaps the best quarterback ever. Wilson’s [No. 50] snaps have decreased over the last few weeks, but he was susceptible to Brady’s mastery, as well. This play-action pass over the middle went like clockwork, with Howard playing the role often filled by Rob Gronkowski.

There was improvement in the second half, but only after the Bucs went ahead, 28-7, and took their foot off the gas. And when they needed a long drive late to ice the game, the Eagles couldn’t get off the field. The hope for the Eagles is that the next few months will offer easier competition and a chance for Gannon and Co. to grow and find answers for the future.

One thing seems certain, however: He needs better linebackers.