Yet another season-altering Eagles medical mystery/debacle is unfolding, nearly a year after the sudden discovery that a lingering back injury to quarterback Carson Wentz was serious enough to shut the quarterback down for 2018.

When wide receiver DeSean Jackson didn’t feel right after playing four snaps in the opening drive of Sunday’s victory over the Bears, Jackson sat out the rest of the game, and went for tests Monday.

By midafternoon Monday, Jackson was scheduled for surgery Tuesday that probably will end his season. ESPN’s Adam Schefter reported that Drexel medical professor William Meyers, who is the surgeon used by most pro athletes for core muscle injury repair, will operate on Jackson.

People close to Jackson hope he can return to the field this season, perhaps for the playoffs. Medical sources said Monday that a return is possible in six to eight weeks, but one source cautioned that a player cannot be 100 percent, good as new, in that time frame. To get to 100 percent requires about three months of recovery, the source said.

Jackson suffered the injury in Week 2 at Atlanta. He gathered medical opinions then, and at least one doctor he consulted recommended surgery. If surgery had taken place then, Jackson might be close to returning now, and he could reasonably expect to be as good as new before the playoffs.

But Jackson opted to try to heal the muscle through rest and rehab. Medical sources have said it is rare for an athlete such as Jackson, who depends on speed and explosiveness, to be able to function effectively without surgery for a core muscle tear.

Yet, that was the course the Eagles and Jackson followed, with head coach Doug Pederson initially leaving the impression that Jackson might be sidelined only a few weeks. David Chao, a former Chargers team doctor who speculates on the internet on NFL injuries, often accurately, has said from the start that Jackson will probably need a repair.

The Eagles have made major changes to their medical staff each of the last two offseasons. They do not grant media access to their doctors or athletic trainers.

Monday, the Eagles released a statement that read in part: “Following the game in Atlanta, DeSean met with the Eagles and multiple independent specialists to determine the best course of action. After gathering all the necessary information, the decision was made to proceed non-operatively through rehabilitation. DeSean worked hard for six weeks to progress to a point where all parties were comfortable with him returning to practice…”

Last Wednesday, 45 days after Jackson left the Atlanta game, he returned to Eagles practice, on a limited basis. On Friday, Pederson touted Jackson’s “great week of practice,” though he was never listed as a full participant.

When Jackson spoke to reporters later that day – his only extensive comments since his injury – he said “that’s the plan right now” when asked about playing against the Bears. “It’s been a long process, so we’ll see how it goes Sunday,” he added.

It went poorly. Jackson ran two short out-routes, drawing a pass interference penalty on one and catching a 5-yarder on the other. By the end of the 14-play drive, he was on the sideline grimacing.

The Eagles’ statement reiterated Pederson’s postgame contention that Jackson was held out of the rest of the game for “precautionary reasons.” When the coach made his weekly Monday morning appearance on WIP-FM, he went on to predict that Jackson would play against New England on Nov. 17, after the bye week. By his noon news conference, Pederson had backed off that claim, deferring to further testing.

The Eagles’ statement said that “after further testing and discussion [Monday] morning, it was determined that the best course of action for a full recovery is to proceed with surgery.”

It seems likely surgery was the best course of action from the beginning. Asked Monday if Jackson should have had surgery after the Atlanta game, Pederson said: “That’s not for me to answer.”

When asked who should answer the question, Pederson said: “I would say DeSean, if he wanted to. ... Players elect to have stuff done. Ultimately, DeSean didn’t want to have surgery when it happened, rehabbed it, and got himself in a position to play. I can’t put words in players’ mouths or doctors’ mouths. That’s not my position.”

On Twitter, Jackson pledged Monday to return “stronger than ever," and said: “If you mad that’s understandable. I’m more Angry than anybody, but it’s GODS plan, not mine!! Trust...”

Without Jackson, the Eagles’ passing game has been pedestrian. It’s hard to envision the Eagles shaping up as a formidable postseason force with the weapons available to Wentz right now.

On Monday, before he knew Jackson was having surgery, Pederson agreed with questioners that the team needed to look at making changes to the wide receiving corps during this bye week. The NFL trade deadline passed last Tuesday, but there are players familiar with the offense who aren’t on teams right now – such as Jordan Matthews, Torrey Smith, and Mike Wallace. And there are practice squad receivers -- Greg Ward, Marcus Green, and Robert Davis.

Jackson turns 33 on Dec. 1. The Eagles drafted him in the second round in 2008 and he became a Pro Bowl talent. But he ran afoul of then-coach Chip Kelly after compiling the best season on his career in 2013, when Jackson caught 82 passes for 1,332 yards. Kelly released Jackson, who played for Washington and Tampa Bay before returning to the Eagles in a trade this year.

He signed a three-year, $27.9 million Eagles contract that contains an out following the 2020 season, according to Spotrac.com. If he is released then, Jackson, the franchise’s seventh-ranked all-time receiver, will have made $17.9 million from the deal and the Eagles will accrue a $5.802 million dead cap charge.

Developing storylines

  • The key to Sunday’s victory was the 16-play, 8-minute, 14-second drive that pretty much ran out the clock before Jake Elliott’s final field goal, of course, but don’t overlook the play that got the ball back – Avonte Maddox’s deflection of a third-and-9 pass to Bears tight end Adam Shaheen.
  • New Eagle Genard Avery split a sack with Malcolm Jenkins while playing only three defensive snaps.
  • Eagles tight ends Zach Ertz and Dallas Goedert were targeted 16 times and combined for 13 catches. Wide receivers Alshon Jeffery and Nelson Agholor also were targeted 16 times. They caught seven passes.
  • The Eagles seem to be a much better tackling team with Maddox, Jalen Mills, and Timmy Jernigan in the lineup.
  • The Bears complained that Jason Kelce was subtly moving the ball, after they were flagged for neutral-zone infractions four times in their first three possessions. If that happened, it was too subtle to be visible on the broadcast replay.
  • Fox analyst Mark Schlereth was trying to liken the Eagles’ pass rush to sharks circling, but disgruntled Bears fans might have concurred with his description of struggling quarterback Mitchell Trubisky as “a bag of chum,” regardless of the whole shark thing.
  • That was 59 combined snaps for Eagles wideouts Mack Hollins (42) and J.J. Arcega-Whiteside (17), no catches, and no targets.

Who knew?

That core muscle injuries usually require surgery?

Pretty much everyone who has paid attention to pro sports over, oh, the last 25 years or so.

Obscure stat

That missed extra point Sunday was Jake Elliott’s second such miss in as many weeks (he’s 20-for-22 this season). Elliott has not missed a field goal (12-for-12).

Extra point

The Eagles and the Patriots both have bye weeks, leading into the Pats’ visit to the Linc on Nov. 17. The Pats went into their bye off their first loss of the season, 37-20 on Sunday night at Baltimore.

Judging from social media, some Eagles fans thought the Pats’ loss was a bad omen. Now New England will be especially fired up and focused for a nonconference game in Philly. (One would think Bill Belichick and the remaining Pats from the Super Bowl LII team would be fired up regardless, but, whatever.)

There is, of course, another way to look at the Ravens’ 17-point victory. Namely, that it showed New England is far from unbeatable. What was supposed to be the best defense in the league by a wide margin gave up four touchdowns – as many as the Patriots’ D had given up in the seven previous games combined.

The first time the Patriots played a really good team, they got whacked. And this is a bad thing for future opponents?

As for the hand-wringing about how motivated New England will be in two weeks, to find the Pats’ most recent back-to-back losses, you have to go all the way back to … hold on I have it here somewhere, ah yes -- last December, when they lost, 34-33, at Miami, and were so focused and enraged that they lost the next week at Pittsburgh, 17-10.

The 5-4 Eagles might have a hard time with the 7-1 Pats. But it won’t be because New England is coming off a loss. It will be because the Eagles don’t seem to be all that good.