Jets quarterback Christian Hackenberg throws a pass during the first...

Jets quarterback Christian Hackenberg throws a pass during the first half at MetLife Stadium on Aug. 26, 2017. Credit: Daniel De Mato

If the Jets’ express goal of the preseason was finding out whether Christian Hackenberg is ready to be an NFL starter, they have their answer:

He is not.

With more practice reps in recent weeks and a second straight start in Saturday night’s annual preseason game against the Giants, Hackenberg offered unmistakable proof that he should not be the Jets’ opening day starter when they face the Bills in Buffalo on Sept. 10.

It remains an open question whether Hackenberg will ever become a functional NFL starter, and that answer won’t be known for some time. But the Jets would not be doing anyone a favor — not themselves, and especially not Hackenberg — if they go into the season with him as their starter.

Either they go with 38-year-old veteran Josh McCown, who is at least functional and can serve as a bridge from now until there is someone capable of leading this team for the longer term, or they take a shot with Bryce Petty, who actually has been decent as the season has progressed, albeit against second- and third-team players.

It is simply not Hackenberg’s time. And there is increasing concern it may never be.

A week after a shaky performance in Detroit, where he was sacked on his first dropback and did not lead a single possession that resulted in points, Hackenberg was exposed by the Giants. With both teams using their starters through the entire first half in the most significant dress rehearsal before the regular season begins, Hackenberg was positively brutal. Against the Giants’ starters, he was 8-for-15 for just 60 yards and two interceptions, both of which were returned for touchdowns by Giants’ defensive backs. He was also sacked three times.

Hackenberg did come in to relieve Petty after he was injured, and he led the Jets on a touchdown drive to bring them a late touchdown to get the Jets to within 32-31 with 1:26 to play. But that doesn’t negate what happened against the big boys in the first half.

“The best way I’ve heard [quarterback development] described is it’s a marathon, not a [sprint],” Hackenberg said after the game. “You need to be able to take the good, take the bad, learn from the bad and build on the good. Keep your head up and push through things, because it’s not always going to be peaches and cream. You have to be able to come back from mistakes and things that didn’t go your way, and I think that’s really what defines you as a player and a person.”

Hall of Fame coach Bill Parcells had an expression he often use to describe players in Hackenberg’s situation, and the analogy seems appropriate at a time like this: “He’s like a ball in tall grass . . . lost.”

Right now, Hackenberg is lost.

He has offered definitive evidence that any improvement he made from a rookie season in which he never even saw the field during the regular season and had only minimal work in practice has been nominal at best. Granted, he was playing against a defense that is considered among the best in the NFL; even so, the mistakes and misreads were glaring to the point of alarm.

Just as he did in last week’s start against the Lions, Hackenberg was sacked on his first dropback. Last week, the pressure came from the right side. This time, the Giants ran a safety blitz at Hackenberg’s blind side, and he didn’t feel the pressure coming when Darian Thompson bore down. The result was a five-yard sack.

Two possessions later, Hackenberg dropped back on first down from his own 24 and looked in the right flat for tight end Eric Tomlinson. But the quarterback failed to see safety Landon Collins lurking close by, and Collins jumped the route as soon as Hackenberg delivered the ball. He stepped in front of Tomlinson, picked the ball off, and raced 23 yards into the end zone.

“I knew [Collins] was rotating down, and I had lost sight of him,” Hackenberg said. “By the time I let go of it, [Collins] was breaking on it. It was a great play. I got to learn from that.”

Hackenberg looked reasonably functional on his only scoring drive of the preseason when he drove the Jets 66 yards in 10 plays to set up Chandler Catanzaro’s 27-yard field goal early in the second quarter. Dating back to last preseason, Hackenberg had gone 33 possessions before putting points on the board.

But then came another mistake. He stared down receiver Robby Anderson on an in-cut to the middle of the field, but didn’t get the ball there quickly enough. Giants cornerback Janoris Jenkins belted Anderson, forced the ball loose, and cornerback Donte Deayon caught the ball out of the air and returned it for a 36-yard touchdown to give the Giants a 29-3 lead.

Last year, the Jets invested a second-round pick in the former Penn State quarterback, and they have a lot riding on whether the 22-year-old Hackenberg pans out. He’s still a very young player, and it’s still very early in his career. But in a league where the pressure to get quarterbacks going as soon as they’re able, the Jets don’t have the luxury of time.

Had general manager Mike Maccagnan not overdrafted Hackenberg and instead taken him lower in the draft, this might not be such a big issue. But with the Jets in the midst of a sweeping roster overhaul, and with potential answers at quarterback available in next year’s draft, the need to find a franchise passer has never been more pressing.

Especially now that there is further evidence that Hackenberg is not the answer.