If Eli Manning were in the game, he would not get sacked eight times against the Cardinals.

If Manning were in the game in the third quarter when Chandler Jones easily shed a block attempt by tight end Evan Engram and made a beeline for the quarterback, it likely would not have resulted in a sack and lost fumble, as it did for Daniel Jones. Manning probably would have sensed the pressure and thrown the ball at the feet of one of his closest targets, killing off the play rather than accepting a loss.

It is a sight Giants fans groaned about often the past few years, seeing Manning spike the ball rather than get hit and push his offense back.

If Manning were on the wet field at MetLife Stadium this past Sunday in the 27-21 loss to the Cardinals, he would not scramble for 10 yards on third-and-8 in the first quarter. Three plays later, had he been in the game, Manning most likely would not zero in on Golden Tate even though Tate is double-covered and would not throw the ball to linebacker Jordan Hicks for an interception, a pass Jones conceded was “just a force. I shouldn’t have thrown it.’’

Five starts into his NFL career, Jones cannot know everything Manning accumulated in 16 seasons, just as Manning could never gain the physical advantage of speed and running prowess that Jones unveils when he leaves the pocket. There are always tradeoffs when a veteran quarterback is cast aside and a first-year player is pushed onto the field.

The Giants have not reached 300 total yards in their last three games, all losses. They have not reached 165 net passing yards in any of the three games. The offense was without Saquon Barkley for two of the losses and thus Jones gets graded on a bit of a curve. But the reality is when coach Pat Shurmur decided to bail on Manning merely two games into the season, he set his team up for a 14-game learning curve that was going to be challenging to watch.

There is no doubt Shurmur believed Jones possesses the inherent smartness that would minimize some of the typical rookie mistakes. This is not happening. Jones is making the mistakes typical of novice NFL quarterbacks — not protecting the ball with two hands when under siege, not seeing the entire field when throwing into danger areas — and the Giants are feeling the pain of this process. This is how an offense scores only 14 points against the league’s 30th-ranked defense.

Once again, Shurmur put the Giants in a be-careful-what-you-wish-for situation. The eagerness to see Jones, the No. 6 pick in the NFL Draft, was tangible and tempting, but seeing him for 14 starts might be seeing too much.

More out of as bad a loss as the Giants have had this season:

– There is a stubborn quality to the way Shurmur is dealing with replay challenges. We get it, the league has a problem overturning pass interference calls or non-calls. We get it, Shurmur technically had a case — a good one — that Janoris Jenkins should not have been called for pass interference, and in fact Arizona receiver Trent Sherfield initiated the contact and actually slipped and fell without any assistance from Jenkins.

“I guess I am going to continue to do it,” Shurmur said. “I know they are getting overturned at a low percentage, but I felt like there was a push there and it was a big chunk of yardage. It was in the first half, and I felt like it was worth challenging at that point. I knew we had jumped offside and it was kind of one of those free-play scenarios. But, I thought it was worth the risk at that time. It just didn’t get overturned.”

Shurmur has to realize these calls are not going to get changed. When his challenge failed, it made it 26 of the past 27 coaches’ challenges on pass interference penalties that were not overturned. Shurmur is 0-5 in challenges this season, including 0-4 on pass interference challenges. Why continue to slam his head into a wall?

“Because I think it still makes sense in situations like that, where those are large chunks of yardage, to give it a shot,” Shurmur said,

Okay then.

– The eight sacks of Jones were the most allowed by the Giants in nearly five years. Manning (six times) and Ryan Nassib (two times) were sacked a combined eight times in a 27-0 loss to the Eagles in Philadelphia on Oct. 12, 2014. The last time a Giants quarterback was sacked eight times was Dec. 14, 2008, when the Cowboys did it to Manning in a 20-8 Giants loss in Dallas.

– The Cardinals increased their lead to six points with a field goal with 2:13 remaining and at that time, rookie Darius Slayton should have been instructed to take a knee if the ensuing kickoff reached the end zone. The Giants were out of timeouts, with only the two-minute warning to stop the clock for what would be a last-ditch series to score the winning touchdown. Slayton was not told to accept a touchback and the results were bad.

“[Special teams coordinator Thomas McGaughey] pretty much just gave me the option, stay in or bring it out,” Slayton told The Post. “Felt like I had a chance to bring it out and get a solid return, just didn’t quite pan out that way.”

No, it did not pan out that way.

He fielded the ball one yard deep in the end zone, got little traction on his return and was dropped on the 12-yard line. The return used up 11 seconds and gave the Giants 2:02 to work with. Had he stayed in the end zone, the Giants would have had the ball on their 25 with 2:13 left.

“I think it was good,” Shurmur said of Slayton’s decision. “Trying to make a play. That’s what you try to do. It was a yard in, right? But he’s done a good job with the opportunities he’s gotten, and there was a chance for him to make a big play and score a touchdown from a yard in. I was okay with it.”

Slayton has “done a good job with the opportunities he’s gotten”? Where? When? How? Before this game, Slayton had never had a kickoff return in an NFL regular season game. He was back there only because another rookie, Corey Ballentine, is in the concussion protocol. Slayton did have a 30-yard return earlier in the game, but it is not like he is a seasoned veteran. He should have stayed in the end zone.

For more on the Giants’ Week 7 loss to the Cardinals, listen to this episode of the Giants podcast, “Blue Rush”: