NFL

NOW WE’LL FIND OUT: MAN OR MANGENIUS ?

KELLEN Clemens should be the Jets’ starting quarterback Sunday afternoon in Cincinnati. He won’t be, which means the honeymoon period Eric Mangini has enjoyed as the Jets’ new head coach is officially over. No more flattering cameos on “The Sopranos.” No more Mangenius. He’s on his own now.

Those calling for Clemens to replace Chad Pennington as the starter should save their voices. Mangini made it clear yesterday he’s sticking with Pennington for the indefinite future.

“All decisions are based on what gives you the best chance to win the next game,” Mangini said.

Benching Pennington, an eight-year veteran who is 32-26 as a starter, is the popular opinion, judging from the talk shows and e-mails after Sunday’s 16-9 loss to the Eagles. Someone’s blood should be spilled for a disappointing 1-5 start. Pennington is the target because of six interceptions over the last three games and an inability to get the Jets in the end zone enough against the Eagles. Clemens’ big arm and untapped potential could provide the spark this team needs.

Of course, the backup quarterback always becomes the favored son in times like these and it doesn’t always turn out as well as Tom Brady replacing Drew Bledsoe or Tony Romo replacing Bledsoe. If Bledsoe were the Jets quarterback, the decision would be easy. In this case making no decision is making a decision – one that could define Mangini’s early head coaching career.

The Jets were looking for answers yesterday. They’ve practiced hard, paid attention to detail, done all the coaches have asked. Yet, they’ve missed tackles on Sundays, thrown interceptions and dropped passes. They’re all but out of the playoff race. Now what?

Pennington could have been sacrificed. Instead, Mangini made the less popular and more difficult choice to stick with him. Whether the leash is shorter is uncertain.

“I’ll continue to assess the whole situation,” Mangini said, “not just with that position, but with every position.”

Keeping Pennington as the starter is a reminder to each player that everyone is to blame. It’s starts from management on down. Where was Pete Kendall when the Jets needed one yard to help tie the game? Fundamental breakdowns, including missed tackles, and ineffective play calling, are on the coaches.

“There are a lot of different areas where we need to get better,” Mangini said. “It’s not a one-person issue. It’s a collective issue.”

Now we’ll find out what kind of coach Mangini really is. He’s 11-11 overall and facing his first crisis, though you wouldn’t know it from his calm and in-charge demeanor yesterday. He was peppered with questions about Pennington’s status, but hardly flinched at the darts thrown by the media.

Mangini said he has an open-door policy and is willing to listen if any of his players has a gripe.

“I’d welcome that because I’m sure their input would be very important and I’d love to hear from them personally,” he said.

So far no players have paid him a visit.

With three winnable games – at Cincinnati and home against the Bills and Redskins – Pennington and the Jets can start to salvage something from their season before a bye week. It’s a critical stretch that could prove whether Mangini can motivate this team in its darkest hour. Losing the locker room in his second season as a head coach could doom his tenure. If the Jets can stay together and win, they may learn something about themselves and their coach that could make them a stronger team in the future.

“It’s not important when adversity strikes,” Mangini said. “It’s important how you deal with it. As a group we’re going to deal with adversity by continuing to correct the things we need to correct and working on the things we need to work at.”

For now Mangini is no longer Mangenius. Now we’ll find out what kind of coach he really is.

george.willis@nypost.com