Giants’ young offensive line is a big mystery

Stop us if you’ve heard this one before.

The Giants assemble what they believe is a dreamy group of offensive playmakers. The quarterback declares this could be something special. It all appears copacetic until it is time to put the plan in motion and get the ball from the hands of the quarterback into the hands of those paid to make some magic with it.

Then it goes from the promise of good to the reality of bad.

This is a cycle the Giants need to break, if they are to turn the optimism of this offseason into actually winning in the real season.

Their pass-catchers at wide receiver are led by newly signed Kenny Golladay, plus Sterling Shepard and Darius Slayton — seemingly something for everyone — with John Ross possibly adding a deep-threat presence. There is speed (Evan Engram) and steadiness (Kyle Rudolph) at tight end. And, oh yes, there is the return to health of Saquon Barkley, eager to reclaim his perch as an elite NFL running back.

There is more than enough for Daniel Jones.

Just like there seemed to be more than enough for Eli Manning in 2018 — with Odell Beckham Jr., Shepard, Engram and Barkley as a dynamic and terrific rookie. There were some flashes, but ultimately the offensive line was so unreliable that what went on up front — more specifically, what did not go on — compromised the productivity of players clearly capable of much more.

For all the Giants added to help surround Jones with weapons, what have they done this offseason to protect him, to ensure he has enough time to scan the field? What has been done to create space for Barkley, coming off reconstructive knee surgery, or to allow the towering Golladay an extra second to get down the field to make one of his contested grabs?

The most notable offensive line move by the Giants? The release of Kevin Zeitler, their starting right guard, a veteran with no Pro Bowls on his résumé but plenty of solid work to show for himself. This is not addition by subtraction. This is subtraction by subtraction, necessitated to free up $12 million in salary cap space in order to fill holes elsewhere while creating one where it previously did not exist.

It could be that one of the five starting linemen to open the 2021 season is not yet on the roster, with the draft and the No. 11-overall pick a landing spot for a starting guard or right tackle. Northwestern’s Rayshawn Slater fits the bill and should be there. The risk: injecting more youth directly into a young lineup.

For now, there is Andrew Thomas (22) at left tackle, Shane Lemieux (23) at left guard, Nick Gates (25) at center, Will Hernandez (25) at right guard and Matt Peart (23) at right tackle. Erstwhile starting left tackle Nate Solder (33 on April 12) took a huge pay cut to return after opting out in 2020 and provides security at both tackle spots and insurance in case Peart cannot cut it as a full-time starter. Zach Fulton, 29, a seven-year veteran, could push Hernandez for a starting job, though Fulton is coming off a rough season for the Texans, allowing an NFL-high 11 sacks. This “push’’ might never materialize.

So, unless there is rapid and significant development from Lemieux (he needs work in pass protection) and Peart, and evidence Hernandez can jump-start a stagnating career, how, exactly, can the Giants go boldly into the season confident in this updated scoring plan?

“Here’s what the Giants say: They’re gonna live with their rookies, and they like their third-round pick at right tackle,’’ an NFL source with knowledge of the Giants’ thinking told The Post.

That third-round pick, Peart, could be the linchpin. He looks the part at a long-limbed 6-foot-7, gaining strength to what was a lithe 318-pound frame. Peart, out of UConn, was considered to be a developmental-type prospect, but he ended up getting 150 snaps on offense, making one start (a Week 6 victory over Washington). He graded out superbly against the run but poorly in pass blocking, based on Pro Football Focus ratings, and should benefit from more stable coaching on the offensive line after a turbulent rookie indoctrination.

“They love their line,’’ the source said. “They really think they can ride and die with that line. They think Matt Peart is extremely talented.’’

Other tidbits from the source: The coaching staff is high on Lemieux, thrilled with the energy he brought to the field. The coaching staff has not given up on Hernandez but he needs to prove himself.

“I think the only guy they don’t love is Will,’’ the source said. “They do not think he’s a bad player, they just aren’t sure he should be a starter.’’

It could work. Or not. Shabby play along the offensive line is akin to draining batteries inside an exciting new toy. It does not work correctly, sometimes operates as if in slow motion and eventually stops altogether. The Giants have played this unfulfilling game before.