Howie Roseman and Doug Pederson overestimated the Eagles’ depth | Marcus Hayes

The 2019 Eagles were supposed to be the most talented team of the Jeffrey Lurie era. Better than the 2004 group with Donovan McNabb and Terrell Owens. Better than the team that, two seasons ago, won Super Bowl LII.

Yes, they were the third-oldest franchise in the NFL, but with so many pedigreed players they were considered injury-proof, fail-proof, foolproof. They thought they had a strong stable of receivers, a couple of backup corners who might start on other teams; a defensive line with perhaps too many good young players, and an offensive line upon which immediate success was assured. And they were proud of what they’d built.

“I do feel like it is the deepest roster we have had," coach Doug Pederson said.

Pederson was giddy at the prospect of adding a bona fide deep threat, DeSean Jackson, and signing defensive tackle Malik Jackson, and retaining a group of cornerbacks that might finally be considered decent. So was Pederson’s boss.

“I think we have a lot of talent,” general manager Howie Roseman said.

He thought wrong. The depth was a mirage.

And so, as the Eagles travel to Miami on Sunday, they are 5-6 with little margin left for error. Only consecutive losses by the Cowboys (6-6) have kept them relevant in the playoff conversation. Even if the Eagles reach the playoffs, with so little depth, will it really matter? Can they realistically expect Alshon Jeffery, Jason Peters, and Tim Jernigan to make it through two full months of football?

Incredibly, somehow they overrated virtually every position. The Eagles thought they knew what depth looked like. They’d seen it before.

Chris Long and Michael Bennett as backup defensive linemen last season — that’s depth. Fourth-round rookie Shareef Miller, second-year reserve Josh Sweat, third-year practice-squad product Daeshon Hall, fourth-year reserve Hassan Ridgeway, and veteran Vinny Curry, cast off after one season with the Bucs — that’s not depth. That’s just hoping. Worse, it’s gambling. Malik Jackson and Jernigan were sidelined by the second half of Game Two, which began a six-week run of incompetence along the defensive line.

The defensive linemen weren’t as bad as the defensive backs.

When Ronald Darby injured his hamstring in Game Three, the Eagles lost the third of their top four projected cornerbacks. Jalen Mills and Cre’Von LeBlanc already were dealing with foot injuries. Then the Birds lost corner/safety Avante Maddox to a neck injury in Game Four.

No problem, right? Sidney Jones and Rasul Douglas, taken in the second and third rounds of the 2017 draft, respectively, had to be ready by now. And at the end of training camp Roseman had called veteran safety Andrew Sendejo the biggest surprise of the offseason.

Big problem. Douglas, Jones, and Sendejo played poorly. Now that Darby, Mills and Maddox are back, Jones, who started in place of Mills at the beginning of the season, has been benched. Sendejo got cut after Game Seven.

At least the defensive backfield was supposed to be an area of concern entering the season. The offensive line was not.

Sure, Peters was 37, but the Eagles traded up three spots to draft Andre Dillard with the 22nd pick, a player they believed could immediately play either tackle position. But when Peters (inevitably) missed 3½ games Dillard struggled as his replacement at left tackle. Then, when right tackle Lane Johnson exited Game 10 with a concussion and veteran backup Halapoulivaati Vaitai replaced him, Big V was so bad in relief that Pederson prepared Dillard to play right tackle in Game 11. Pederson had to bench Dillard at halftime of Game 11 and reinsert Vaitai. It was a mess.

Johnson returns Sunday. Peters will play, too. But the damage has been done.

The greatest damage, of course, came at the receiver position. The Birds lost fragile 32-year-old free agent DeSean Jackson early in Game Two and have never recovered. Jeffery has missed almost four games with injuries, Nelson Agholor has had a catastrophic season. Mack Hollins is invisible, and second-round rookie J.J. Arcega-Whiteside has been a five-catch bust.

Worst of all, the Eagles refused to promote training camp standout Greg Ward from the practice squad until Game 11. Ward caught six passes in Game 11, the most catches by a wide receiver in five games.

The only thing worse than lacking depth is failing to recognize it when you have it.