The fourth quarter and final stage of the 49ers’ destruction of the Eagles was just about to commence Sunday night when Jalen Hurts, with a thick jacket draped over his back, jogged down the sideline, down a tunnel, and to the home locker room. For a few fleeting minutes, here was the Eagles’ nightmare scenario playing out before everyone’s eyes at Lincoln Financial Field. Here was Hurts, about to be examined for a concussion, out for who-knew-how-many plays in this 42-19 49ers victory, out for who-knew-how-many practices or games as the Eagles’ season hits its home stretch.

The quiet terror in the stadium didn’t last long. Marcus Mariota filled in for Hurts for just five plays before Hurts returned to the field, reentered the game, and even completed a touchdown drive. But even that brief period of uncertainty about Hurts’ health and availability was enough to throw the Eagles’ standing in the NFC in stark relief.

It doesn’t go far enough to say that they can’t afford to lose Hurts, either to a concussion or for any other reason. Without him, they can kiss their chances at a Super Bowl goodbye. The takeaway from Sunday’s result, though, was that even with him, they might not possess the depth and talent necessary to beat the 49ers should the teams meet again in the postseason. After spotting the Eagles a six-point lead, after keeping them out of the end zone as they advanced inside the 20-yard line on each of their first two drives, San Francisco was that dominant. And even with a healthy Hurts, the Eagles might not be able to close that gap.

Which is why Nick Sirianni’s decision to reinsert Hurts into the game, once the quarterback had been cleared to return after undergoing an evaluation for a concussion, was such a great risk. Hurts had taken a wallop from Fred Warner and Oren Burks on a 5-yard carry late in the third quarter, with the Eagles down by 15 points. It was a two-score game when Hurts left, but it was a three-score game, a 35-13 deficit, when he came back with 8 minutes, 38 seconds to go.

“It’s kind of who he is,” wide receiver A.J. Brown said. “Me, honestly, I didn’t want him to come back in. He took a big shot, and the game’s pretty much over, and I didn’t want to risk him getting banged up a little more or whatever the case may be.

“That just shows you: He didn’t want to leave his teammates out.”

Yes, it was a sign of Hurts’ guts and resilience that he was willing to play again. “I thought he operated fine when he came back in,” Sirianni said. But to ask him to lead a successful comeback at that point would have been the equivalent of asking him to turn water into a fine Bordeaux. As it was, he wasn’t interested in proving to his teammates that he could continue playing or to the 49ers that they couldn’t knock him out. He was interested in fulfilling his obligation as a starting quarterback. The game goes on, so you play on.

“I don’t know about showing anybody anything,” Hurts said. “It’s more so that the game’s not over. Just trying to keep fighting.”

That mindset is what any team would want from its quarterback. But it’s also what made Sirianni’s decision so dangerous. Hurts is the nexus of the Eagles offense. They need him on the field. They need him throwing and running. They need him making big plays in big moments, just as he did last week against the Bills. Just as they’ll need him to do at AT&T Stadium next Sunday against the Cowboys. Just as they’ll need him to do in the playoffs, no matter who their opponents might be.

More, they’re likely to need him to be as good as he’s ever been. He wasn’t that Sunday: He slipped and fell, taking a 15-yard sack on the Eagles’ second possession and forcing a Jake Elliott field goal. He held the ball in the pocket for ages on a couple of dropbacks, only to come away with nothing productive. He wasn’t bad by any stretch, throwing for 298 yards and a touchdown, but not bad clearly won’t get it done against the 49ers.

The Eagles defense struggles to stop an offense that can attack the middle of the field — and the 49ers offense attacks the middle of the field, with Christian McCaffrey and George Kittle and Deebo Samuel — as well as any. And did. This is a defense that looked gassed Sunday after spending so much time on the field seven days earlier against the Bills. This is a team that has to have Hurts to have any hope of winning a championship and has to have him be great. It’s asking a lot of him, but it’s the burden a franchise quarterback must bear.

“Find ways to win — that’s always the mentality; that’s always the approach,” he said. “This is a moment when you go back and reflect on it and learn from it, like every win. You treat them all the same. When you win or when you lose, it’s about ‘What can I learn from this?’”

We learned that the Eagles might just need Jalen Hurts to be perfect to beat the San Francisco 49ers. At a minimum, they need him to be available. Out of this one-sided loss to a team that might be the class of the conference, that was the only good news: He still is.