NFL

BRASS KNUCKLES

Smoke and mirrors got the Jets to the playoffs in the first season of the Mike Tannenbaum-Eric Mangini regime. And a crash and burn to 4-12 in 2007 put those two into the looking glass.

Reality caused the Jets to spend $140 million on free agents this summer to shore up both fronts and provide a pass rush. Whether Brett Favre, at almost 39, primarily was the football department’s idea or Woody Johnson’s attempt to ease the sting of personal seat licenses, the coach and general manager will get their hands caught if one of the smallest windows of opportunity in NFL history slams down without some playoff wins.

Though Johnson seems enamored with the duo, the fans will not be if Favre, realistically set up to fail because of his age and short preparation time, doesn’t take the Jets any further than Chad Pennington could have. Theoretically, Kellen Clemens remains in preparation, but if the quarterback of the future had excited anyone in his eight starts last year, Favre would not be here.

But here he is – attracting a glare that will obscure Tannenbaum’s best work, his drafts. Even if D’Brickashaw Ferguson, taken fourth overall to anchor the offensive line for a decade, has yet to dominate, he may still, and Nick Mangold (29th overall), Darrelle Revis (14th), David Harris (47th), and Leon Washington (117th) were excellent picks.

Alan Faneca and Damien Woody are offensive-line upgrades, but players just past their primes regardless. So may be Kris Jenkins, a much rounder peg at 350 than was the barely 300-pound Robertson at the nose tackle spot Mangini stubbornly insisted on employing in his beloved, Patriot-style, 3-4.

Jonathan Vilma, a free-ranging building block, and Dewayne Robertson, a too-small nose tackle, are gone, casualties of that system. So if Calvin Pace, the guy with the most upside amongst the incoming free agents, and first-round pick Vernon Gholston are what Mangini believes, he has the players finally to play his defense.

If he doesn’t, then Mangini is another coach who proved better as a Hall of Fame mentor’s assistant and Tannenbaum just another front-office worker bee who rose to the level of his incompetence.

These are two meticulous and controlled men, for whom a wild fling with the aging all-time flinger, Favre, doesn’t fit the profile. But they didn’t resign in protest, so Brett is their guy now, too, just like in Year Three this is Mangini’s and Tannenbaum’s team – and already, a referendum on their reign.

jay.greenberg@nypost.com

MORE: Complete Jets Coverage

PLAY POST PICK ‘EM