NFL

Jets will likely stay with Ryan, but other coaching options are worth consideration

REX FILES: Rex Ryan’s job seems to be safe, but if the Jets’ woes worsen, owner Woody Johnson may consider replacing his head coach with a candidate such as Sean Payton (top right) or Chip Kelly (bottom right). (Neil Miller)

What if the bottom falls out? What if 4-7 becomes 4-9 and ends in 5-11 and the national embarrassment from Thursday night perpetuates for the Jets?

What then? What does Jets owner Woody Johnson do if what already has been a categorical failure of a season continues to get worse?

Does he put another Band-Aid on the program and find a minor scapegoat as he did last year when offensive coordinator Brian Schottenheimer was asked to leave? Or does he make major changes and blow up the entire operation?

Johnson wants to keep head coach Rex Ryan, and he should. Continuity counts in the NFL. Look at the most successful franchises in the league — the Patriots, Steelers, Giants and Packers, to name a few — and see how often they change head coaches.

If Johnson does opt to change coaches, his first call should be to Sean Payton.

The likelihood of Payton coming to the Jets is not great because he is most likely to return to the Saints once his suspension from the “Bountygate’’ is complete. And if he does not return to New Orleans, Payton landing in Dallas, where he was an assistant and still has ties to owner Jerry Jones, would seem like the next logical step.

But if Johnson is seeking a new head coach, check first with Payton, not only because he is a proven winner but because the Jets have not hired an offensive-minded head coach since 1990, when they brought in Bruce Coslet to replace Joe Walton.

Every head coach the Jets have hired since Coslet has, for the most part, come with a defensive background: Pete Carroll, Bill Parcells, Al Groh, Herman Edwards, Eric Mangini and Ryan.

The NFL is an offensive league now. Prolific offenses win championships more often than defenses do.

If Johnson wanted to opt for a high-risk-high-reward candidate at head coach, he could look into Chip Kelly of the University of Oregon.

Kelly is regarded as a coach who would succeed in the college-to-pro transition because of his organizational skills and creative offensive mind, but he has been a head coach for just four seasons at the collegiate level.

Kelly turned down the Buccaneers job last offseason, but will be pursued by an NFL team again after this season.

Another fascinating possibility is Bill O’Brien, a former Bill Belichick assistant who has done an amazing job at Penn State in the post-Joe Paterno era. The likelihood of O’Brien leaving Penn State after just one season, however, is low.

Should Johnson opt to keep Ryan, which he likely will, he should insist on replacing offensive coordinator Tony Sparano, who has been an abject failure as Schottenheimer’s replacement.

With the struggling Chargers likely to fire head coach Norv Turner, the Jets should bring him in as offensive coordinator because he excels as a coordinator but struggles as a head coach.

What Johnson will do regarding general manager Mike Tannenbaum is compelling. By all accounts, Johnson likes Tannenbaum running the football operation and surely does not want to flat-out fire him.

Tannenbaum is a good man who has done good things for the organization. But based on his recent drafts and player personnel decisions, which have left the roster without enough depth or skill-position talent, it seems the Jets need someone else having final say on personnel.

That could mean reassigning Tannenbaum in the organization (remember, Tannenbaum got the GM title when Terry Bradway was moved to the scouting department) to handle the player contract end of the operation, which always has been his strength, and finding someone else to pick the players.

Should Johnson remove final say on personnel from Tannenbaum, there are several candidates with strong personnel backgrounds.

49ers director of player personnel Tom Gamble, who used to work for the Jets and knows the market, has been a scout, a coach and has been involved in contract negotiations.

Another interesting possibility is Eric DeCosta, the Ravens assistant GM, because he has worked closely under general manager Ozzie Newsome, considered by many one of the best talent evaluators in the league. It would not be easy to pry DeCosta away: He is viewed as the imminent replacement for Newsome whenever Newsome retires, and his wife is from Baltimore.

An outside-chance candidate is former Jets tight end and scout Brian Gaine, who is the Dolphins’ director of player personnel and has been paying his dues in the league, also having worked for Parcells.