Eli Manning of the New York Giants reacts after a...

Eli Manning of the New York Giants reacts after a third quarter touchdown against the Dallas Cowboys on Sunday, Dec. 11, 2016. Credit: Jim McIsaac

If there’s one thing we have learned about Eli Manning over the years, it is never underestimate his ability to recover from misfortune. The proof is everywhere:

Spinning out of the grasp of Patriots defensive end Jarvis Green with Super Bowl XLII on the line and then connecting with David Tyree on one of the most amazing plays in NFL history in an improbable win over the unbeaten Patriots.

Somehow finding a way to thread a pass into the microscopically small window just inside the left sideline to Mario Manningham in yet another upset win over the Patriots four years later in Super Bowl XLVI.

Shaking off the effects of his worst statistical season in 2013, when he had only 18 touchdown passes and a career-high 27 interceptions, and then totaling 65 touchdown passes the following two seasons under offensive coordinator Ben McAdoo.

Anywhere you look in Manning’s career, he has managed to rebound from poor throws and poor performances, whether it be a four-interception debacle in 2007 against the Vikings, after which general manager Jerry Reese called Manning “skittish” in the pocket, or a five-interception fiasco in 2013 against the Seahawks, which may have been the worst game of his career.

Manning almost certainly — and deservedly — will wind up in the Pro Football Hall of Fame, but there is no denying the moments that make you wonder how with all that talent and intelligence he can produce so many clunky efforts.

And here we are yet again at a crossroads for Manning, who presides over a 9-4 team coming off a 10-7 win over the then 11-1 Cowboys, but who is now in many ways the weak link on a team now defined by a championship caliber defense. Manning did manage to throw what turned out to be the game-winning pass on a third-quarter slant route that Odell Beckham Jr. turned into a 61-yard touchdown, but he was mostly terrible the rest of the night.

He finished with three turnovers — two lost fumbles and an interception — but his stat line would have looked far more gruesome if the Cowboys’ defensive backs had better hands. It easily could have been a four-interception night for Manning, and he could have lost the game and dealt his team a blow in its chase for its first playoff appearance since 2011.

Manning’s offense had been the strength of the team the previous two seasons, with an inept defense at the heart of the team’s back-to-back 6-10 seasons. But there are legitimate concerns about whether Manning can snap out of a malaise that has lasted the entire season in which the Giants have been unable to crack 30 points after doing so seven times last season on the way to scoring 420 points. The Giants have been held to 22 or fewer points nine times this year, totaling only 24 points the last two games.

With Manning less than a month away from his 36th birthday, it’s fair to wonder whether we are seeing a lasting decline in his play, or whether he will somehow find a way to recapture the quality that defined him as one of the NFL’s top quarterbacks.

Manning saw how older brother Peyton succumbed last year to injury and ineffectiveness at age 39, even if the elder Manning showed enough wherewithal to help Denver to a Super Bowl championship in his final season. Peyton turned into a game manager during his final season as his body betrayed him, and it was Von Miller’s defense that was at the heart of the team’s title run.

Eli is not to that point and still may have two or three more years left in him. But if the Giants are to make a run this season — and this will be one of the last times he’ll have this chance — then he will have to produce the kind of moments that helped his team win two previous titles.

It’s unwise to bet against him, but it’s certainly appropriate to wonder if he still has it in him. Even if Manning himself still believes he has.

“I am confident we can have that game, where things do click and we make the plays that are there,” Manning said Monday on his weekly radio spot on WFAN. “It’s really just making the plays that are there and not making the mistakes that are costing us points and that are costing us chances to convert on third down and move the ball. I think we can do it. I think we’ve been close.”

In fairness to Manning, the problems on offense are not all his doing. His line has been a problem all year, which was again the case against the Cowboys, when Manning was under constant pressure. Dropped passes were a problem against the Cowboys; even Beckham dropped two, one of which would have gone for a touchdown. And wet and icy conditions on Sunday night weren’t ideal.

That said, the outcome of this season and any potential playoff run still rests with Manning. As good as the Giants’ defense has been — and it’s been championship caliber, especially in pitching a near shutout against the Cowboys — it will take championship play from the quarterback to create the chance to win it all.

Manning simply hasn’t played up to the standards he himself has set. At this point, he needs a miracle finish, but the Giants need to understand that he may not be capable of another one in him.