Daniel Jones showed up as The Natural in his preseason debut, and the unmistakable rumble of his thundering footsteps cannot possibly go in one of Eli Manning’s ears and out the other.

No one is calling Daniel Jones a draft-day reach anymore, only a precocious rookie reaching for Manning’s beloved job.

One perfect preseason series Thursday against the Jets hardly means that Pat Shurmur is currently prepared to make the franchise-quaking change from Manning to Jones.

That will happen whenever Jones shows he has climbed the tallest mountain in the NFL landscape:

When it becomes obvious that he gives Shurmur and the Giants their best chance to win, meaning a better chance to win than Manning gives them.

Bill Parcells used to tell everyone that you learn about a quarterback when he is bloodied and bludgeoned, and when Jones faces that moment of truth, which he faced at Duke, there are no indications he will flinch.

Every Manning pass, every Manning series, will mean everything from this point on. Daniel Jones has turned up the heat on him sooner than anyone not named Dave Gettleman could have imagined.

Shurmur and Gettleman have been seduced and intoxicated by Jones’ eye-opening development, as well they should be.

Even Giants fans, even the boo birds who trashed the pick, have quickly changed their tune.

They have seen the future, and it is him.

He knows the offense.

He looks unflappable.

The moment doesn’t appear too big for him.

He has arm talent.

He is accurate.

He stands tall and fearless in the pocket.

He keeps his eyes downfield.

And because of it all, he has quickly won the respect of his teammates.

Jones strafed mostly backups in the secondary, yes, but he also didn’t have the services of Saquon Barkley or Sterling Shepard or Evan Engram.

It made me wonder: Did Shurmur declining on Friday to definitely commit to Manning as his Week 1 starter mean nothing, or something?

“Nothing has changed,” Shurmur said.

Nor should it.

Asked if there could be QB competition for Week 1 if Jones continues his expected improvement, Shurmur said: “Well listen, we’re not gonna play the what-ifs, and I would say this — nothing has changed.”

For now.

For now.

Q: Is Eli definitely the starter for Week 1?

A: “In my mind we’re getting everybody ready to play, and our situation here hasn’t changed,” Shurmur said.

Earlier, prior to the Week 1 queries, Shurmur answered it was important to get Manning one (three-and-out) series.

“He’s our starter,” Shurmur said.

For now.

It is inconceivable and madness that the Giants would bring Manning back as a $23.2 million backup. This is no time to be kicking him to the curb. The smart money absolutely should be on him starting the season. But there should be smart money on him not finishing it as well.