If the recent Leonard Williams trade is an indication, the Giants and Jets no longer are afraid of helping each other, there’s a way to finish the job.

Do all fed-up New York football fans a favor and truly combine forces.

With the Giants headed for an eighth straight season without a playoff win and the Jets on the way to a ninth straight without a playoff appearance, The Post pondered a fun hypothetical: Would the best possible 53-man roster made up of Jets and Giants, and assembled under the NFL salary cap, be a playoff team?

“No,” ESPN analyst and former Jets center Damien Woody said without hesitation.

The Jets enter their once-every-four-years meeting with the Giants at 1-7, fresh off a loss to the tanking Dolphins. The Giants are losers of five straight, falling to 2-7 entering the 1 p.m. Sunday kickoff at MetLife Stadium.

At least we know a combination roster isn’t the worst team money can buy.

Here is The Post’s projection of what a New York Gets (do you prefer New York Jiants?) roster would look like, without regard for current injury. Starters listed in bold:

KICKER (1): Aldrick Rosas, Giants($645,000)

Easy choice, even with the 2018 Pro Bowler Rosas missing two field goals and two PATs so far. The Jets are on their fourth kicker since the offseason began.

PUNTER (1): Lac Edwards, Jets ($738,951)

Having the best season of his four-year career, Edwards gets a slight edge over Riley Dixon.

LONG SNAPPER (1): Zak DeOssie, Giants ($735,000)

The second-longest tenured Giant (13 seasons) is a two-time Pro Bowler handling this job exclusively for a decade.

CORNERBACKS (6): Janoris Jenkins, Giants ($14.75M); Brian Poole, Jets ($3.5M); Darryl Roberts, Jets ($4.5M); DeAndre

Baker, Giants ($1.91M); Nate Hairston, Jets ($645,000); Grant Haley, Giants ($570,000). Total: $25.875M

Poole is a physical tackler who has done a nice job playing zone coverage out of the slot. Jenkins is one of the most inconsistent players in the NFL, and that’s a big price tag. He was shredded by the Buccaneers’ Mike Evans, and his effort is lacking at times, but he has four interceptions and wants the other team’s best receiver. Roberts is the Jets’ leading tackler — though not a fan favorite after his tirade — and the struggling rookie Baker is a first-round pick (his only saving grace). Haley is solid on special teams and a sure-tackler from the slot against the run.

SAFETIES (4): Jamal Adams, Jets ($6M); Marcus Maye, Jets ($1.7M); Jabrill Peppers, Giants ($1.45M); Michael Thomas, Giants ($2M). Total: $11.15M

It was strange when the Jets went safety with their first two picks of the 2017 draft, but it has given them a strength for years to come. Well, unless Adams and the Jets are headed for a divorce after an ugly trade deadline. Thomas is a Pro Bowler on special teams and a quality extra defensive back. Peppers is a great athlete who desperately wants to develop into a great safety.

INSIDE LINEBACKER (5): C.J. Mosley, Jets ($13M); Avery Williamson, Jets ($8M); Ryan Connelly, Giants ($489,253); Harvey Langi, Jets ($570,000); Blake Cashman, Jets ($570,773). Total: $22.629M

Here is a position neglected for far too long by the Giants, whose last Pro Bowl inside linebacker was Antonio Pierce in 2006. Connelly is a rookie fifth-round pick who was starting before a season-ending ACL tear.

Williamson is out for the season and Mosley has been limited to two games by injuries. They were the Jets’ big free-agent signings the past two offseasons. Langi is a core special teams player.

EDGE RUSHERS (4): Markus Golden, Giants ($3.28M); Jordan Jenkins, Jets ($2.2M); Lorenzo Carter, Giants ($928,064); Oshane Ximines, Giants ($704,195). Total: $7.112M

Teams pay big money for edge rushers. Well, most teams. Not these teams. The Giants are tied for No. 15 in the NFL in sacks thanks to free-agent steal Golden, who has at least a split-sack in six of the past eight games.

Carter and Ximines are third-round picks in back-to-back years. Jenkins leads the Jets with three sacks. No wonder they rank No. 29 in sacks.

DEFENSIVE LINEMEN (5): Dexter Lawrence, Giants ($2.4M); Leonard Williams, Giants ($14.2M); Quinnen Williams, Jets (5.91M); Foley Fatukasi, Jets ($613,563); Dalvin Tomlinson, Giants ($1.24M). Total: $24.363M

Quinnen Williams was the higher draft pick (No. 3), but Dexter Lawrence (No. 17) is the NFL’s best rookie defensive lineman, moving much quicker than a 342-pounder should.

Leonard Williams’ Giants debut went much like his four-year Jets career: He created pressure and defended the run well, but no stats to prove it. Every player in his group is on his first contract and 25 years old or younger.

TIGHT ENDS (4): Evan Engram, Giants ($2.92M); Chris Herndon, Jets ($613,718); Ryan Griffin, Jets ($1.35M), Kaden Smith, Giants ($436,770). Total: $5.319M

Engram is among the most explosive tight ends in the NFL. Just a few too many drops and injuries preventing him from being with the elites.

Herndon hasn’t played this season after a strong rookie season, opening the door for Griffin’s three touchdown catches.

WIDE RECEIVERS (6): Sterling Shepard, Giants ($3.39M); Golden Tate, Giants ($6.27M); Jamison Crowder, Jets ($6.78M); Robby Anderson, Jets ($3.09M); Darius Slayton, Giants ($553,497); WR Quincy Enunwa, Jets ($2.8M). Total: $22.883M

One potential problem: Shepard, Tate and Crowder all operate best out of the slot. So what? Time to show versatility, which Shepard already has to make room for Tate.

Slayton is one of the best Day 3 steals of the 2019 draft, with a Giants-best three touchdown catches. Enunwa has missed almost two full seasons (2017 and 2019) with neck injuries but beats out Demaryius Thomas, who was acquired by the Jets to take his spot.

OFFENSIVE LINE (9): Nate Solder, Giants ($12M); Kelvin Beachum, Jets ($9.5M); Kevin Zeitler, Giants ($5M); Will Hernandez, Giants ($1.69M); Jon Halapio, Giants ($645,000); Brandon Shell, Jets ($2.08M); Alex Lewis, Jets ($2.02M); Nick Gates, Giants ($496,666); Chuma Edoga, Jets ($711,750). Total: $34.142M

The offensive line for the Giants has been mediocre at best — and yet four of the five starters come from that side, which is a true indictment of the Jets’ situation. Both teams need to acquire more long-term answers in the offseason, like the 2018 drafting of Hernandez.

Neither Solder nor Beachum are living up to their contracts, but are the best this town has to offer when it comes to protecting a young quarterback’s blind side. Zeitler is the best of the bunch.

RUNNING BACKS (4): Saquon Barkley, Giants ($7.08M); Le’Veon Bell, Jets ($8.96M); Wayne Gallman, Giants ($749,912); Eli Penny, Giants ($645,000). Total: $17.434M

The Wing-T or an option offense? It won’t work in the NFL, but whoever is coaching this team better be creative enough to capitalize on having two of the five best running backs in the NFL paired up.

Shared backfields are more popular in the NFL than workhorses, but a Barkley-Bell tandem surpasses any real tandems like Miles Sanders-Jordan Howard (Eagles). Penny is a fullback with soft receiving hands.

QUARTERBACK (3): Daniel Jones, Giants ($4.66M); Sam Darnold, Jets ($6.87M); Alex Tanney, Giants ($547,058). Total: $12.077M

Darnold is regressing in Year 2 and already has missed six of a possible 24 games due to injury/illness. Jones has been too turnover-prone as a rookie, but his ball placement, especially on deep balls in tight windows, is elite.

Jones-Darnold will be a debate raging in this town for years, especially because the Giants passed on Darnold. On this team, let’s leave cap space to take both because quarterback is too important to be short. Tanney can be the cheaper player-coach in the room.

Key Giants missing

Eli Manning’s $23.2 million cap hit is almost double that of Darnold plus Jones. Crazy money for a backup quarterback over the final 14 games of the season.

Another Giants’ co-captain, Alec Ogletree, pays the price because the Jets have better inside linebackers. Tight end Rhett Ellison is cap casualty and right tackle Mike Remmers loses out to a youth movement of backups.

No room for young defensive backs Sam Beal, Corey Ballentine or Julian Love, either. Too much overlap.

Key Jets missing

Cornerback Trumaine Johnson has been a bust since signing a five-year, $72.5 million contract. His former Rams teammate, Janoris Jenkins, takes up the big-money contract in an otherwise affordable secondary.

The Jets convinced two-time All-Pro Ryan Kalil to come out of retirement to solve a huge hole at center. It looks like he hasn’t recovered from the time on his couch, so it would be a waste.

Brian Winters takes the fall for a disastrous Jets offensive line. Same goes for Henry Anderson on the pass rush. Neville Hewitt was the last Jet cut.

NFL salary cap: $188.2M

Total cap used: $185M

Number of Giants: 29

Number of Jets: 24