FOXBORO, Mass. — Each January, a bit of preemptive Patriots nostalgia creeps across New England.

No one knows how much longer this thing will last. It never will be repeated, and fans are aware of the possibility that this winter could represent the final chapter for any of the key figures. That will be the feeling until the dynasty actually does end.

Of the key figures, Rob Gronkowski’s future seems most uncertain. It’s fair to wonder if we’re witnessing his final days in the NFL, or at least in a Patriots uniform.

He publicly contemplated retirement a year ago and didn’t end up committing to a return until April. Normally a nightmare matchup down the middle, unquestionably the greatest tight end of his generation, Gronkowski has been held in check throughout the season.

His stats are plummeting, down nearly 23 yards per game from last year. He has fewer TDs than fullback James Develin. And he owns a 2019 salary that escalates to a base salary of $9 million, which the Pats seem unlikely to pay.

Tom Brady recently reaffirmed his desire to play next season, but Gronkowski was reluctant to follow his quarterback’s lead at a press conference Thursday.

“I haven’t been thinking of that at all,” Gronkowski said. “We’re on the last game, Week 17, we’ve got the Jets. That’s all I’m really worried about as of now.”

When questions about Gronk’s future popped up later in the press conference, the four-time All-Pro tight end said, “I love the grind. I’m all-in. I’ve been all-in all season, whether it’s been up or down. And I’m going to tell you this right now: I’m going to be all-in for the rest of the year, no matter when it is, and that’s my main focus.”

Generally jovial with the media, Gronkowski wasn’t quite as goofy – but much more reflective.

He didn’t grow visibly frustrated with questions about lack of production or confidence. He didn’t open up entirely, but went about as far as any Patriot will go in front of microphones and cameras. At several points, Gronkowski referred to the 2018 season as a “rollercoaster” season.

He said half the battle during such a year is finding the right mindset.

“Yeah, you could have the physical tools and everything, but if you’re not mentally there all the way, then you’re not going to be able to use those physical tools how you want to use them,” Gronkowski said. “So definitely, you’ve just got to stay positive.

“You learn a lot of things every single year about yourself, as you get older, too, how you adapt to things … You can never get too down on yourself. I mean, yeah, you can get down on yourself a little bit to get you re-motivated and stuff. But that has happened to me before, where you get too down and dig yourself a bigger hole. So you’ve just got to stay balanced.”

Gronkowski declined to disclose when his confidence had bottomed out.

“I probably have before, but it’s over. I’m back on the rollercoaster, baby. I’m going. I’m here for the ride,” he said, laughing.

Does Gronk have another dominant stretch left in the tank?

The Patriots sure could use it. The passing offense, briefly reinvigorated in a 34-33 loss at Miami, has stagnated over the past two weeks. The Pats will miss Josh Gordon, who was their most prolific receiver. In their first game without Gordon, Gronkowski saw three targets. Two fell incomplete. A third slipped through his hands and was intercepted.

If the Patriots are going to make a deep playoff run, they’ll need much more from Gronk. This weekend’s matchup with the Jets represents one final chance for Gronkowski to get in a groove before the playoffs arrive. And this very well could be the final playoff run for Gronk in New England.

Not that he’s thinking about that right now. For now he’s simply pushing ahead to the next game.

“We’ve been through a rollercoaster, up and down throughout the whole season,” Gronkowski said, “and what you’ve got to do is just stay focused, and keep on preparing and keep on mentally and physically just grinding and just keep going.”