The mistake the Rangers made with Lias Andersson was not so much the way they deployed the Swedish center but in drafting him seventh overall in 2017.

That, less than three years into Andersson’s pro career, would be the Original Sin.

The young man renowned for his leadership ability more than any singular on-ice skill did not only request a trade out of the organization, a reasonable ask, but also simply picked up and left the AHL Wolf Pack following that appeal.

That’s quite a display of leadership, even for a frustrated 21-year-old, who is now under suspension by the Rangers. You can quibble about the amount of ice time he received and his bottom-six usage through his 66 NHL career games in which he averaged 10:33 per game while posting nine points (three goals, six assists), but you cannot quibble with the nature of Andersson’s unacceptable flight of fancy out of Hartford.

Do you — and did he and his camp — not think that general manager Jeff Gorton has been seeking a deal for Andersson since his Nov. 17 assignment to Hartford? Do you think Andersson’s trade value, at a low ebb anyway, was helped over his last 10 AHL games in which he recorded only three points, with the two goals and one assist coming in the same game on Dec. 7?

What do you think the market is for a player who lacks speed and explosiveness, is not particularly creative with the puck, and who walked out on his organization a day after the Dec. 19-27 NHL holiday trade moratorium kicked in?

Perhaps the Predators would be willing to discuss an exchange for Finnish winger Eeli Tolvanen, the 30th-overall selection of that same draft, another one whose star has dimmed — Nashville refused to make him available for a Rick Nash rental deal in 2018 — and who has been stuck in AHL-Milwaukee all season.

Regardless, the Andersson selection — a surprise at the time after the Blueshirts acquired that selection plus Tony DeAngelo from the Coyotes in exchange for Derek Stepan and Antti Raanta that has since been endlessly inspected — has turned into a dark hole.

Indeed, much as with Dylan McIlrath at 10th-overall in 2010, Al Montoya sixth in 2004, Hugh Jessiman 12th in 2003 and even Pavel Brendl fourth and Jamie Lundmark ninth in 1999, the Rangers seem to have swung and missed like Casey of the Mudville nine.

But at least the Blueshirts did not come away empty from the draft floor in Chicago. No, they did not. Because with their own 21st-overall pick, the Rangers selected Filip Chytil, who serendipitously ended a 10-game goal drought on Sunday with a beauty that gave his team a 1-0 lead at 7:14 of the first period in what became a 5-1 rout of the Ducks.

A rebuild season that has stayed above water largely because of the dynamic offense provided by Artemi Panarin and Mika Zibanejad and the superior goaltending tandem of Henrik Lundqvist (for this one) and Alexandar Georgiev needed an injection from the kids, certainly in light of the disquieting exit by Andersson.

Chytil provided that with a burst down the right side before beating Ryan Miller with a backhand. Then, 91 seconds later, Brett Howden built on that by jumping on a long rebound and firing it in from the left circle to end his own 15-game drought.

Andersson gone. Chtyil and Howden, not.

Howden has been a flash point this season simply because he earned the time from David Quinn that Andersson did not. But Howden was and has been the more effective player. Let’s remember, though, that this 21-year-old is regarded as a bottom-sixer, rather than a centerpiece of the rebuild.

Chytil, on the other hand, is a top-six skills player with size, speed, hands and attitude. A centerpiece. When he was demoted to the Wolf Pack following a disappointing camp, he did not sulk. Rather, he worked on his game. And here he is, with nine goals in 26 games, and apparently fine physically after surviving a crash into the wall after seeming to catch his skate in a rut early in the third period.

“That was a sick move,” Lundqvist said of Chytil’s dash down the right that toasted Adam Henrique and singed Miller. “He’s skilled. He’s so skilled. And I think this year he is taking a big step as a player.

“He’s just stronger on the puck, more confident, he’s making plays and he can also make a play like that. He’s grown into a big player for us here. Going in the right direction.”

And he is saving the Rangers’ first round of the 2017 draft.

For more on the Rangers, listen to the latest episode of the “Up In The Blue Seats” podcast: