Optimists might argue these disappointed yet improved Giants are a few pieces short of a Super Bowl run.

Pessimists could contend that with 17 unrestricted free agents and needs at several key positions, a slide out of playoff contention is as likely as a return to the postseason in 2017.

The Giants, who went 11-5 in Ben McAdoo’s rookie coaching season but got blown out, 38-13, in the Wild Card round in Green Bay, certainly built what GM Jerry Reese and McAdoo have called a promising “foundation.” But that guarantees nothing for next season if Reese does not build on the progress made in 2016.

And even Reese, who hit big with blockbuster free agency signings last offseason and some fruitful draft picks in the rookie class, admitted Monday that he won’t have the flexibility to act as boldly this spring.

“We don’t have as much money as we had last year to go shopping in free agency, but I think that we will be able to do things that we need to get done to help this football team,” Reese said.

Last offseason, Reese signed DE Olivier Vernon, DT Damon Harrison and CB Janoris Jenkins to major free-agency deals. He then selected plenty of rookies who became starters or major factors (Eli Apple and Sterling Shepard most prominently) and also inked undrafted talents that stepped up (such as Andrew Adams and Romeo Okwara).

A general manager’s work never ends, though, and the pressure is on Reese again, particularly since the Giants’ list of Top Five Greatest Needs starts at one of the sport’s most important positions.

Eli Manning, 36, might be “on the back-nine” of his career, but Sunday proved he still can bring it in the postseason. Manning was throwing darts and looked ready to win a shootout if need be against Aaron Rodgers until Odell Beckham Jr. and his teammates on offense let him down.

Reese has to continue thinking Super Bowl next season even as he builds through the draft for the future. That means fixing Reese’s greatest mistake last offseason, his decision to ignore major needs on the offensive line.

Reese drafted Ereck Flowers ninth overall out of Miami (Fla.) two years ago, but even the GM allowed Monday that “it is time for him to show us the fruits of being a first-round draft pick.” “We will evaluate that,” Reese said. “Is he the left tackle? Should he be in a different position? We will evaluate that.”

Drafting a tackle again in the first round this soon (the Giants have the 23rd pick in April) wouldn’t be the Giants’ preferred course of action. Adding inexperience to a critical position wouldn’t be the best method either, with Manning up there in age.

So could the Giants score a reasonable deal perhaps with 11-year veteran left tackle Andrew Whitworth, 35, the career Cincinnati Bengals free agent who has not missed a start in the past three years and graded among the highest of all NFL offensive linemen this season?

Minnesota’s Matt Kalil, 27, is a free agent coming off hip surgery but is much younger and had started all 66 of his first 66 NFL games through four-plus seasons prior to the injury.

Or, would the Giants look in the draft anyway, where top-rated tackles by Scout Inc. include Alabama’s Cam Robinson, Wisconsin’s Ryan Ramczyk and Notre Dame’s Mike McGlinchey?

The Giants can’t give up completely on Flowers, but finding a reliable left tackle would allow McAdoo to shift Flowers to right tackle, a position in flux this season between Marshall Newhouse and Bobby Hart but with no ideal solution.

Right guard John Jerry is a free agent, also. So the Giants have plenty of work to do on an offensive line that did not consistently protect Manning and led a 29th-ranked rush offense (88.2).

Jason Pierre-Paul wants a long-term deal for big money, but the Giants aren’t going to be able to pay him the same $85 million over five years that they gave Vernon to lure him in free agency from the Miami Dolphins last year.

Pierre-Paul was having a Comeback Player of the Year type season before he got hurt in Week 13 at Pittsburgh, but he also wasn’t playing at a level consummate with that type of contract until a two-week span against Chicago and Cleveland in Weeks 11 and 12, when he had 5.5 of his seven sacks, a fumble return for a touchdown, and 12 tackles.

Reese said when asked if he considers it possible to re-sign both Pierre-Paul and DT Johnathan Hankins: “I think so.” But while Pierre-Paul wants to remain a Giant, he is more likely to get a bigger offer elsewhere.

That doesn’t mean Reese can leave his defensive end position alone, though.

While Vernon had a good year and impressed playing through a broken hand/wrist early in the season, he was invisible in Green Bay on Sunday. And the Giants pass rush this year was not consistent, after being non-existent early in the season.

Okwara is promising, and Owa Odighizuwa will contribute again, but a defense that finished tied for 14th in sacks (35) needs more depth and efficiency at the position.

Spending big money isn’t the solution. A draft deep at defensive end, led by top-five overall projections Myles Garrett (Texas A&M) and Jonathan Allen (Alabama) could yield a diamond in later rounds.

Florida State’s DeMarcus Walker, whom CBS Sports projects as a second-round pick, finished second in the NCAA with 16 sacks. Notre Dame’s Isaac Rochell could fall down the board and is even projected in places to go undrafted but may be a low-risk, late steal.

Martellus Bennett, 29, is truly the one that got away.The ‘Black Unicorn’ caught 55 passes for 626 yards and five TDs in his only season as a Giant in 2012. He then signed in Chicago and played three years as a Bear, catching a whopping 90 balls in 2014 alone. Now, he’s starring with Tom Brady and the New England Patriots in place of the injured Rob Gronkowski.

Presumably, the Pats and Bennett both will recognize their fit and reunite past this season. The point is, though, a 6-6, 275-pound tight end who makes life hard on a defense is something this Giants offense sorely misses.

Receivers Odell Beckham Jr. (5-11) and Sterling Shepard (5-10) are both small targets. Will Tye was the most reliable tight end but has a ceiling. Rookie 2016 draft pick Jerell Adams is 6-5 but still maturing in the offense, hurt his shoulder late, and the jury is still out. The Larry Donnell experiment has to end, no?

Will Johnson should provide a tight end/fullback combo option returning healthy, but Manning needs a big target out in the pass game, too.

Dominique Rodgers-Cromartie is scheduled to cost an expensive $8.5 million against the cap next season, per overthecap.com. But even as a third corner, DRC proved critical to the defense’s success in 2016, he is a popular teammate, and he should be worth retaining.

Victor Cruz ($9.4 million), Dwayne Harris ($3.8 million) and Rashad Jennings ($3.0625 million), on the other hand, are deals that Reese must revisit.

Cutting Cruz seems inevitable. Harris had a good season covering kicks, but he makes too much money for what he provided – or didn’t provide – as a return man in 2016, in addition to his lack of usage on offense.

Jennings is a leader, and he ran well in Sunday’s first career playoff game (when McAdoo gave him an opportunity, that is. But he may make too much for a veteran who lost his starting job by year’s end.

I do believe the Giants found something promising at running back in Perkins, but at the skill positions they have to keep their eyes open.

Would they look on the level of 6-3 Chicago receiver Alshon Jeffrey, one of the projected top free agents along with Pittsburgh RB Le’Veon Bell? Hard to see, but saving money in some places could open opportunities elsewhere.

Reese needs to plan for Manning’s eventual successor at quarterback even though it probably doesn’t mean drafting someone this April. Forecasting that far into the future, though, also requires evaluating Beckham’s deal.

The Giants’ best player is entering the fourth year of his rookie contract, so Reese could consider an extension.

“We will keep all of our options open with respect to those things,” Reese said when asked about extending Beckham.

Manning is under contract until 2020.

Beckham’s off-field and maturity issues most certainly will play a factor in those deliberations. The Giants also know that their offense would be absolutely nowhere without his special talent. So It’s a complex conversation when considering the bigger picture, that’s for sure.

Reese also needs to make sure he’s on the same page with McAdoo: If the coach wants a fullback, for example, the GM should get a reliable one. Linebacker wasn’t a strength this season and the defense still excelled, but that doesn’t mean they shouldn’t shoot high.

At free safety, rookie Darian Thompson should return healthy and start, which would save McAdoo from making the mistake he made in Green Bay – removing his season-long starter Andrew Adams and playing Leon Hall instead.

And above all, Reese needs to get the kicker signing right this time.