One move tends to trigger another in the NFL, even if those moves are by different teams clear across the country. Such might have been the case last week when the Houston Texans hired Brian Gaine to be their general manager and, in a corresponding move, extended the contract of head coach Bill O’Brien by four years.

Not bad for a coach who entered the final stretch of a 4-12 season on the hot seat, openly campaigning to return to the job by any means — even if it meant coaching the 2018 season in the final year of his prior deal. Both Gaine (who received a new, five-year deal after returning following one season with the Buffalo Bills’ front office) and O’Brien now are synced up through the year 2022.

One reason for doing that is to have the GM and head coach tied together, and both Gaine and O’Brien have spoken well of each of each other publicly and are believed to have a good working relationship in earnest. That bond is expected to be a lot stronger than that of O’Brien and outgoing GM Rick Smith, who took a leave of absence to take care of his sick wife but will retain his executive vice president title.

But there also might have been another reason for the timing of the move, and it didn’t have anything to do with the announcement of Gaine to his new post. In the days prior, there had been whispers involving O’Brien and another job — not an opening for this season but for down the road.

As the New England Patriots’ two coordinators, Matt Patricia and Josh McDaniels, started firming up their round of head-coaching interviews over the past few weeks, there simultaneously was talk floating around the league about who might eventually replace Bill Belichick as Patriots head coach. In the wake of the ESPN story regarding perceived tension in the building, owner Robert Kraft assured Patriots Nation with a few strong statements that both Belichick and Tom Brady would be back in 2018.

But just as Tom Brady’s eventual replacement doesn’t appear to be on the roster, it’s not entirely clear if Belichick’s successor is either. Assuming Patricia (strongly rumored to be the Detroit Lions’ next coach) and McDaniels (ditto with the Indianapolis Colts) sign four- or five-year contracts and have some modicum of success there, it’s hard to imagine Belichick — who turns 66 in April — waiting for either to return and replace him.

That’s where O’Brien’s name started coming up. Their mutual admiration is strong, and Belichick has always spoken highly of him when asked. There had been some chatter that it was O’Brien, and not one of their current coordinators, who could end up being the head coach A.B. (After Belichick).

That, of course, still could happen. Teams change course all the time, and O’Brien’s path with the Texans could veer in the next year or two if they can’t get back to their winning ways. But the Texans made the savvy move of extending O’Brien’s contract to assure that if the Patriots wanted him in a year (or two or three or whatever), they’d likely have to send some kind of draft-pick compensation their way.

That talk, we were told, had merit to it. That’s not to say that Belichick doesn’t also have other ideas of who should replace him one day, but it’s hard to say that he won’t just walk off into the sunset and not care who the Kraft family selects in his place.

It might be more of a testament to Belichick’s greatness if the team went with someone outside the family, so to speak, and then watch the Patriots dynasty crumble. But then again, it also could back up his legendary preparation if he handed over the golden keys of the franchise to one of his former lieutenants and then saw the empire live on with his teachings still resonating.