Josh McDaniels and Matt Patricia are both entrenched in the rumor-filled world of head coaching vacancies. The Patriots’ offensive and defensive coordinators, respectively, are receiving interview requests from multiple teams. With interest from the right teams, both could leave New England for head coaching jobs, ESPN’s Adam Schefter speculated.

As rough as it would be to lose one or both coordinators, Nick Caserio would be a more detrimental loss to the Patriots.

The Patriots’ director of player personnel is being considered for general manager positions around the NFL, and so far has one interview request in San Francisco. While McDaniels and Patricia have been calling plays and developing players, Caserio has stocked New England with a group of enormously talented and promising players since he took the job in 2008.

McDaniels and Patricia are hooking fish — but that’s largely because Caserio stocks the pond.

“Nick [Caserio] does a tremendous job,” coach Bill Belichick said Tuesday. “He and his staff do a tremendous job of, first of all, seeing hundreds and hundreds of players from the draft choices on a perspective draft class to all of the players in the league on all of the teams. . . . I don’t think anybody, I can’t imagine any personnel person in the league that sees more players than he does both in the spring scouting process part of it for the draft and then just watching tape on players throughout the course of the year.”

The Patriots don’t have a general manager, which makes them somewhat unique. Belichick is the head coach and the GM — he’s the end-all-be-all. But Caserio holds the highest personnel position in the franchise. To use a Game of Thrones comparison, Caserio is “The Hand of the King.” Caserio helps inform every decision Belichick makes.

Under Caserio’s leadership, the Patriots have drafted standout first-rounders such as Jerod Mayo, Devin McCourty, Nate Solder, Chandler Jones and Dont’a Hightower. They’ve taken second-rounders Sebastian Vollmer, Rob Gronkowski, Jamie Collins and Jimmy Garoppolo. The Patriots have drafted late-round players such as Matthew Slater, Julian Edelman, Marcus Cannon, Nate Ebner, James White, Trey Flowers, Joe Cardona, Shaq Mason and Malcolm Mitchell. That’s ignoring undrafted free agents Malcolm Butler, David Andrews and so many others.

“It’s a huge volume of number of players that they have to dig through, but they do it tirelessly,” Belichick said Tuesday. “I think Nick and his staff have done a great job on that.”

It’s hard to comprehend the young talent the Patriots have acquired when it’s just a handful of names. And the names that aren’t listed include a number of busts like former first-rounder Dominique Easley, who the Patriots released ahead of the 2016 season. But for the most part, the Patriots have hit on first-round picks. They’ve traded around the draft to acquire more picks and locate players who fit their scheme. Belichick gets all the credit — and he deserves a lot of it — but you can bet he’s making the moves with the help of Caserio.

The tandem has a talent for staying ahead of the curve. They find players who will be “the next man up” after their best players depart by trade, in free agency or retire. That provides continuity in the Patriots system where they’re able to develop players to play key roles in their offense or defense.

Edelman, drafted in 2009, replaced Welker by the 2013 season when Welker left for Denver. Hightower, a 2012 first-rounder, replaced Mayo by 2013 when Mayo began missing games due to injury. Former 2015 fourth-rounder Trey Flowers appears capable of replacing both Jones and Easley. Former 2014 second-rounder Garoppolo or 2016 third-rounder Jacoby Brissett could eventually replace Tom Brady.

Because these players haven provided relatively seamless transitions, the Patriots could afford to let big-name players depart and — most often — make their millions elsewhere. Because they let other teams take on mega-contracts, they don’t have to overpay for talented players. Quite the contrary. By drafting excellent youngsters to replace the superstars, they are underpaying many of the players on their roster. It’s one of the best ways to win with rookie wage scales working as they do currently.

But Caserio, who served as director of pro personnel in from 2004 to 2006, has also helped the Patriots bring in a number of different excellent veterans. LeGarrette Blount, Martellus Bennett, Chris Long and Chris Hogan come to mind from the 2016 offseason. But the Patriots have also added players like Aqib Talib, Darrelle Revis, Brandon Browner, Dion Lewis and Jabaal Sheard. He’s also been around when the Patriots have made the calculated decision to pay their veterans to stick around, like Devin McCourty, Julian Edelman and Rob Gronkowski.

Sure there’s misses in Terrance Knighton, Albert Haynesworth and Chad Johnson. But none of those deals were cataclysmic against the cap. They were calculated risks that only negatively affect the short term cap situation. They didn’t derail any of the Patriots long-term plans.

And then, of course, there’s the in-season acquisitions. Just in 2016, The Patriots have signed players like Michael Floyd and Matt Lengel and traded for Eric Rowe and Kyle Van Noy, who have all contributed heavily during the course of the season.

“Nick does a great job of understanding what we’re trying to do, how we’re trying to play, the players that do a great job within our system,” Patricia said Tuesday. “I think it helps them to go out and identify players that maybe they see, whatever that process is, that could help us and fit into whatever it is at that point in the year that we either need, or the direction we’re heading as a particular group or defense or position-specific responsibility.”

The Patriots succeed year after year because Caserio and Belichick have a knack for replacing a player long before he needs replacing. Caserio has the ability to identify current needs and future needs — he’s prescient because that’s what excellent personnel managers do. That’s why any team would be lucky to have him, and his absence would be felt by the Patriots.