They’d lost 80% of their starters. Still, they persisted.

The Eagles’ offensive line always held the key to the team’s hopes in 2021, but when it lost right tackle Lane Johnson to a personal matter just hours before kickoff Sunday, it was without four of five starters and all seemed lost.

Then, somehow, the O-line delivered the best Eagles performance of the game. Its coach, Jeff Stoutland, again proved himself the most indispensable assistant in Eagles history.

“He’s got everybody ready to play in all these different scenarios if different scenarios happen,” head coach Nick Sirianni said after the game. “That’s just a tribute to Coach Stout of how good of a football coach he is.”

It sounds like he’ll have to keep working his wizardry.

The Eagles won’t say when Johnson will return. Right guard Brandon Brooks’ strained pectoral muscle cost him the last two games, and he’ll miss at least one more. Left tackle Jordan Mailata’s injured knee cost him the last two games. Right guard Isaac Seumalo is lost for the season to foot surgery.

The Eagles played the pliant Chiefs last weekend, but they visit the Panthers on Sunday. Carolina’s defense ranks No. 3 in yards and points allowed, and it’s No. 2 against the pass.

» READ MORE: Jonathan Gannon’s defense is reeling, but his frustration lies with himself, not his Eagles players

For the moment, so what? On Sunday, the Eagles’ replacement linemen somehow played better than everybody else.

Better than rookie receiver DeVonta Smith, who finished with seven catches for 122 yards. Better than rookie running back Kenneth Gainwell, who collected 89 yards and a touchdown on just nine touches. Even better than Jalen Hurts, who threw for a career-high 387 yards and added two touchdowns. Hurts, Smith, and Gainwell would not have gotten their numbers if the line had stunk.

The line didn’t stink, and that’s without grading on any curve. Grade it on a curve, and it grades off the charts — especially fill-in starters Jack Driscoll and Nate Herbig.

“Just can’t say enough for how Jack Driscoll and Nate Herbig played,” Sirianni said after watching tape Monday. “They graded out as high for us.”

That’s the straight grade. Here’s the curve.

Incredible

Driscoll came off injured reserve Saturday. He’d practiced all week at right guard, but started Sunday at right tackle. Herbig was supposed to be on the bench. Landon Dickerson, a rookie, played right guard the last 2½ games, but, with Driscoll coming off IR and slated to play next to Johnson, Dickerson moved to left guard during last week’s practices.

So, the Eagles had three players playing positions they hadn’t played all year, with little or no practice time at those spots. Finally, Andre Dillard, considered a first-round disappointment from 2019, was starting for the second consecutive week in place of Mailata.

» READ MORE: Eagles Super Bowl victory over the Patriots still on Tom Brady’s mind

Yet the Eagles did not miss the big names. Any of them.

Sirianni helped lighten the line’s load. He limited deep drops in the pocket, called quick-hitting plays, and used misdirection. But the line still had to function. It did so.

None of Hurts’ three sacks was the line’s fault, and the Eagles gained 481 yards. It’s true that the Eagles gained those 481 yards against the NFL’s second-worst defense, but then, those 481 yards helped make the Chiefs the NFL’s second-worst defense.

Besides, if you’d had to rank the NFL’s offensive lines before the first snap Sunday, you probably would have ranked the Eagles’ makeshift line no better than 31st.

You’d have been wrong.

Big-play machine

It takes time and precision for big plays to work. With alarming regularity, the line gave the weapons time and performed precisely.

The early 22-yard receiver screen to Smith exploded largely because Dillard delivered the most significant block, on shifty cornerback L’Jarius Sneed, while Dickerson took care of linebacker Anthony Hitchens.

The 21-yard seam route to Dallas Goedert on the next play happened because Driscoll stoned Chris Jones’ power rush, while Herbig slid from his right-guard spot all the way over to the left side of the pocket, where he stopped defensive end Mike Danna. Driscoll manhandled Jones again on a 21-yard shot to Smith to start the Eagles’ third quarter.

» READ MORE: Jalen Hurts’ 4 starts followed a clear pattern. For the sake of the Eagles’ future, he needs to break it. | Mike Sielski

The line handled a six-man blitz on Hurts’ touchdown toss to Goedert late in the first quarter, burned a five-man blitz on a 14-yard toss to Goedert that ended the third quarter, and gave Hurts four seconds to throw the 14-yarder to Goedert. That set up Gainwell’s touchdown early in the fourth quarter — a power run behind Jason Kelce, and between Dickerson and Herbig. The line later gave Hurts another four seconds on an 18-yard pass to Miles Sanders, and Hurts was unmolested soon thereafter on a 19-yarder.

The line kept the Eagles’ third drive alive when it bulldozed a 3-yard quarterback sneak; gave Hurts five full seconds to throw a 14-yard pass to Gainwell; and had Dillard and Dickerson spring Quez Watkins on an 18-yard screen that mirrored Smith’s from the opening drive. Herbig hustled 21 yards to cover Hurts’ fumble that ended the first half, keeping the Chiefs from a last-second field-goal try.

Do your job

The circumstances could hardly have been more dire.

Driscoll, a second-year fourth-round pick, missed the last three games of 2020 with a knee injury. He’d started four times last season in place of Johnson, but he hadn’t sniffed a game in more than nine months, since he injured a knee in December. Herbig, undrafted in 2019, started seven games at left guard and five at right guard in 2020, but he’s the Eagles’ ninth offensive lineman. Also, Herbig mainly is a center.

Dillard saw Mailata, a former rugby player with no football experience, get a $64 million contract extension last month. It was a move that likely spelled Dillard’s imminent end as an Eagle.

Perhaps most incredibly, Dickerson — who played right guard, center, and tackle while at Alabama and Florida State — appears to never have played left guard in his life.

Still, they persisted.