ARLINGTON, Texas — We will know soon enough if the Giants were fooled by what their top decision-makers saw — or believe they saw — down the stretch of the 2018 season, as that impression set in motion who and what takes the field Sunday afternoon at AT&T Stadium.

Eli Manning is still around because the late scoring surge convinced general manager Dave Gettleman and head coach Pat Shurmur, with the offensive line finally stabilized, the old quarterback was still able to get his team in the end zone. The Giants last season averaged 27.4 points in their final eight games, and that includes a shutout loss to the Titans. In the first eight games, the Giants averaged 18.8 points. They went 1-7 before Halloween and 4-4 afterward, though they did lose their final three games.

And here we are. Manning returns for a 16th season, for the first time knowing his eventual replacement, Daniel Jones, is on the roster, secured with the No. 6-overall pick in April’s draft.

“I think you can build on the previous year, as long as you’ve done the work,’’ Shurmur said. “I feel like we’ve done the work, because all that you went through a year ago, it’s kind of a memory bank of reps as you get ready for this season. But every season is new. We have to go out and do it.”

Manning is too venerable at 38 to be fooled by late-season illusion. He thinks this can work, operating for a second season in Shurmur’s system, with an upgraded right side of the offensive line.

“Well, I feel it’s just a comfort level in the offense and a lot of those same guys are part of this offense,’’ Manning said. “We have a few new faces that should hopefully help us out and get on track early and play at a high level. Nothing is guaranteed from one year to the next year. Hopefully we can establish that identity soon.’’

The identity, sans Odell Beckham Jr., is going to be far less dynamic. Other than Saquon Barkley, there are no game-breaking type weapons. Sterling Shepard is a solid No. 2 wide receiver now thrust into a No. 1 slot, and though he is dependable, he has averaged just 12 yards per reception in his first three years. Golden Tate is suspended the first four games. One possible threat to provide a jolt, tight end Evan Engram, has the physical goods but must prove he can stay on the field and avoid the lapses that lead to too many drops.

Mostly, it is going to be Barkley right, Barkley left, Barkley up the middle and Barkley as a receiver coming out of the backfield. Manning is at his best as a play-action passer and, at this advanced stage of his NFL life, takes fewer chances down the field.

“I think we’re more on the same page than we were a year ago, just by the nature of having been through it more,’’ Shurmur said. “There’s a quiet confidence that I see in him this year. It takes a while for a new offense to kick in and to get a feel for the thought processes of the play-caller. As the year went on, we got more and more comfortable with that and we blocked better, and you could see more of what Eli could do.”