Rob Ryan’s mane is magnificent — and problematic.  (Ted S. Warren / AP)

In the NFL, the “N” often stands for nepotism and yet the younger sibling of one high-profile name hasn’t cracked the head-coaching barrier yet.

Jay Gruden may have gotten a job, but Rob Ryan, twin brother of New York Jets Coach Rex Ryan, hasn’t gotten so much as a sniff from teams with head-coaching vacancies and there may be any of several reasons for that. For one thing, there’s that cheeky attitude, displayed a year ago when he was fired by the Dallas Cowboys and said he’d have another job “in five minutes.” (Never mind that he did, it’s the attitude that matters.)

Ryan also seems to scoff at discipline, a real no-no in the button-down world of men who run their teams with an efficiency known only to the military. That brings us to the real reason he isn’t getting a head coaching gig. It’s his hair.

“If he wants to be a head coach, he has to cut his hair,” ESPN’s Chris Mortensen said, citing what several executives had told him. “It is about image for these guys. They want a CEO-type. That’s what they want.”

Ryan’s locks don’t bother many people in New Orleans, where he engineered a turnaround from the NFL’s last-place defense to its fourth-ranked.

“Obviously he’s a coach that I think is going to be a head coach,” Saints Coach Sean Payton told ESPN. “Obviously we made great improvements from a year ago. He brings an enthusiasm with him, a personality that is contagious. You know, he’s a great staff person as well, gets along with the coaches.”

But he’s 51 and waiting. Maybe he could do what his brother Rex did. Here’s how he looked in 2005. Note that he got a haircut now and then and still enjoyed life.

Rob Ryan — in the white cap — looked different with the Ravens in 2005. (Toni L. Sandys / Washington Post)

But should he have to stop letting his freak flag fly? Maybe it’s the laissez les bons temps rouler attitude he should ditch. After all, Bill Belichick gets away with cut-off hoodies and we won’t even mention Jim Harbaugh’s puffy $8 khakis. Should Ryan just give in, cut his hair and see what happens?