After a months-long promotional blitz for “The X-Files,” when Sunday’s big NFL game finally arrived, Fox fumbled the handoff. And that’s a surprise, given how long the network seemingly had this date circled on its calendar.

Never mind that the reviews for this eagerly anticipated revival have been pretty tepid. Fox spent months pounding the drums for the program, giving its premiere the plum time period following the NFC championship game, which, coupled with its AFC counterpart on CBS, are usually the second and third most-watched telecasts in any given year, behind only the Super Bowl.

The tub-thumping for “X-Files” included early screenings (back in October at New York Comic-Con and Mipcom, the international TV market), but Sunday’s kickoff was clearly the moment for which Fox had been waiting. Indeed, other than its returning hit “Empire,” the network largely slogged through the first half of the season to reach this moment.

Networks always use big sporting events as an opportunity to promote their shows. It’s one of the ways they can justify the enormous rights fees paid to the NFL. Even if the audience is borrowed, as network execs once described it, that doesn’t mean football fans can’t be held hostage and force-fed on-air promotion, along with all those Budweiser and movie ads.

Certain factors are inevitably beyond the entertainment division’s control, such as the fact that the game itself turned out to be a 49-15 blowout. In addition, Fox Sports’ post-game coverage droned on until 10:24 p.m. ET, offering a longer window for casual viewers to bail.

The real shock, though, was that Fox didn’t do anything special, either during the early part of the game or within its coverage, to promote the premiere. There were no awkward interviews with the talent, no taped pieces, not even shots of David Duchovny or Gillian Anderson sitting in the crowd looking bored.

Admittedly, a lot of those stunts are silly, and Fox did squeeze roughly a half-dozen “X-Files” teaser spots into the game. Yet even those weren’t particularly enticing — it was as if Mark Snow’s score was expected to do all the heavy lifting — and the overall promo payload showered nearly as much attention on the new drama “Lucifer,” an upcoming UFC fight and sister cable outfit FX’s “The People v. O.J. Simpson: American Crime Story.”

In a sense, spreading the wealth around makes a degree of sense. After all, “X-Files” will only run six weeks – or five, really, considering that the second episode will premiere a day after the first. No reason to put too many eggs in that one basket.

“The X-Files” should still open quite well, thanks to a mix of nostalgia and all the promotional work done up until this juncture. Still, after a prolonged and concerted push that essentially began, almost irritatingly so, when Fox announced its 2015-16 primetime schedule last May, the “X-Files” finally landed with less a big bang than a dull thud. And a network that usually prides itself on marketing acumen and ingenuity looked, more than anything, like it had simply run out of gas.