FLORHAM PARK, N.J. — Robert Saleh used to explain the dichotomy of week-to-week reactions in the NFL this way:If you lose, it’s the apocalypse.If you win, you’re going to the Super Bowl.Of course, he didn’t really mean the NFL. He meant coaching in this market, for this team, the New York Jets.With that mindset, the end of the world has been a near-weekly occurrence in Florham Park every fall. But Sunday’s season opener, going up against a Tennessee Titans team now led by Saleh, has a more doomsday feel than usual for the Jets.The reasons aren’t difficult to figure out. On one hand, you have Aaron Glenn, coming off a brutal debut season. After a 3-14 year that ended in five straight losses by a historic margin, Glenn fired half his coaching staff and took over defensive play-calling himself. Ask anyone outside the Jets building which NFL head coach is on the hottest seat, and Glenn might be their answer.On the other hand, Glenn is going against Saleh, a ghost of the Jets’ past, the one that owner Woody Johnson fired unceremoniously less than two years ago. Johnson picked Glenn to replace him and to fix the problems of the previous regime. The Jets have a multi-year plan to get back on track, but the first year was undoubtedly a failure.NFL Week 1 has 'peak nonsense potential'Robert Mays and Derrik KlassenGlenn losing to the man he replaced, and the Jets losing to a Titans team few expect to be competitive this season, would be hard to process for a fan base already overwhelmed by reminders that their team hasn’t made the playoffs since 2010.It does feel fitting that the Jets will have to defeat Saleh to avoid the so-called apocalypse. Though Glenn doesn’t care much about who is on the other sideline.“I get it, it goes with … the territory of Saleh once being here and then I step in as the head coach,” Glenn said. “But to me, I look at it as if it’s a game that we’re going out there to win and it doesn’t matter who it is. That’s the mindset of these players, that’s the mindset of this coaching staff, that’s the mindset of this organization. Our job is to go out there and play this game and be the best that we can be on every play and to go out there and win a game. Nothing else is to be thought of.”Saleh has struck a similar tone.“New York is still a special place, gave me my first opportunity as a head coach,” Saleh told reporters last week. “(But) our desire to beat the Jets is because it’s Week 1 and nothing more. I’m forever grateful for all the opportunity they gave me. I don’t hold grudges.”Even if Saleh won’t say it publicly, it would be fair to assume he’s carrying a little something extra this week — for Glenn and, especially, for Johnson. Saleh went 20-36 as Jets coach and has often viewed Johnson as the biggest reason for the issues of his tenure. Ultimately, he and Johnson never saw eye to eye.As for Glenn: Even if he hasn’t talked much about Saleh directly, he did take some not-so-subtle shots at him during training camp last summer, including moments where he pointed out how often the Jets were penalized previously and how the biggest reason Will McDonald hadn’t taken a leap forward yet was “coaching.” Some carryover Jets players from Saleh’s roster, like Breece Hall and Garrett Wilson, alluded to “instability” and a lack of accountability from the previous staff too.