Carson Wentz isn’t just the most important player on the Eagles roster — he might be the most important player in the NFL. At the very least, he is one of a meager crop of candidates.

Patrick Mahomes, Baker Mayfield, and DeShaun Watson belong to that group. Jared Goff has earned a mention, given his youth and his 4,700 passing yards last season. With Goff, though, it can be difficult to see any superstar potential. And superstardom is the essence of the dilemma that the NFL could face over the next few seasons.

Proclamations of doom for the Shield have been en vogue for years now, with alleged culprits that range from concussions to criminality to civil disobedience. The thing that many of the proclaimers ignore is the favorable economics of the labor market in which NFL owners operate. In short, there is an overabundant supply of 20-something athletes who can run or catch or block or tackle and are willing to risk their gray matter and do as they are told in exchange for a chance at making millions.

We see the reality of this surplus supply late every summer in the turnover on 53-man rosters. Jordan Matthews becomes Torrey Smith, who becomes Mike Wallace, who becomes DeSean Jackson. Bryce Treggs becomes Mack Hollins, who becomes J.J. Arcega-Whiteside. The left tackle of the future is Dillon Gordon, and then it is Jordan Mailata, and now it is Andre Dillard.

“Next man up” is the league’s prevailing ethos in large part because the dominant paradigm among personal departments says that all men are more or less replaceable.

Except for one position.

Among the ramifications of Andrew Luck’s stunning retirement from the game of football at age 29 last weekend was its exacerbation of a potential crisis that has been brewing for more than a decade. Look up and down the list of the NFL’s passing leaders each season and you’ll see a handful of names that have been mainstays since the early part of the century.

The Chiefs' Patrick Mahomes is part of the crop of promising young quarterbacks in the NFL.
Chris Ochsner / MCT
The Chiefs' Patrick Mahomes is part of the crop of promising young quarterbacks in the NFL.

Of the 14 highest-rated starting quarterbacks in 2018, five were in their 14th season or greater. Tom Brady, Drew Brees, Ben Roethlisberger and Aaron Rodgers are all regarded as sure Hall of Famers. If Phillip Rivers played in a different era, he would be, too.

All five of those players will be 36 or older by the end of the 2019 season. Along with Ryan Fitzpatrick in Miami and Eli Manning in New York, nearly a quarter of the league will start the year with a quarterback age 36+. Before this current group of gray-hairs, there had been just seven quarterbacks in NFL history who started more than 16 games beyond the age of 36 (Brett Favre, Vinny Testaverde, Peyton Manning, Doug Flutie, Kurt Warner, Brad Johnson, Jeff Garcia). In other words, for Brady et. al, the end could come any season, including this one.

Which raises the question: Who are the quarterbacks who will replace them?

Ever since he was drafted at No. 1 overall in 2012, Luck has looked as if he would one day lead the pack. As a rookie, he joined a team that went 2-14 the season before and led the Colts to an 11-5 record. In 2018, he rejoined a team that went 4-12 the season before and led it to a 10-6 record. Since the start of the 2011 season, the Colts are 12-30 in games not started by Andrew Luck, and 53-33 with him.

The Colts were 53-33 in games in which quarterback Andrew Luck played.
Michael Conroy / AP
The Colts were 53-33 in games in which quarterback Andrew Luck played.

Forget about what the individual numbers say. Anybody who suggests that we have just suffered anything other than the tragic loss of one of the single most impactful players in the NFL and a future all-time great has not watched enough Indianapolis football over the last nine seasons. And if your reaction to his retirement is anything other than a sense of appreciation for having been privy to his career, I’d encourage you to go spend an autumn standing in the middle of I-76 while trying to keep your eyes downfield. Because that’s how Luck spent each of his before last season.

With any, well, luck, we haven’t seen the last of him. Real life doesn’t follow movie scripts, but it sure would be nice if he realizes that what he really needed was a year away from the pressure of rehab set to a ticking clock and the suffocating need to make a city a winner all by himself.

Beyond that, our best hope is that Luck does not turn out to be the canary in the coal mine, and that Matt Ryan and Russell Wilson remain willing and able to play this sport until a ripe old age. Because after them, the most important position in the sport of football is currently in the midst of a disconcerting state of flux.

Since 2017, 10 of the NFL’s 32 teams have selected a quarterback in the first round of the draft. Factor in the five teams that have an aging star and no clear heir apparent, and the six teams that have installed a new veteran starter (Nick Foles in Jacksonville, Joe Flacco in Denver, Jimmy Garoppolo in San Francisco, Kirk Cousins in Minnesota, Ryan Fitzpatrick in Miami, and now Jacoby Brissett in Indianapolis), and the two with quarterbacks who have yet to sign an extension heading into the option year of their rookie deals (Marcus Mariota in Tennessee, Jameis Winston in Tampa Bay), and you are left with only nine teams that have an entrenched veteran starter in his physical prime.

Jacoby Brissett has taken over as the Colts' starting QB after Andrew Luck announced his retirement.
Darron Cummings / AP
Jacoby Brissett has taken over as the Colts' starting QB after Andrew Luck announced his retirement.

Of those nine quarterbacks, the Raiders’ Derek Carr and the Bengals’ Andy Dalton might have already whacked their heads on the ceilings of their potential. A couple more — Detroit’s Matthew Stafford and Carolina’s Cam Newton — are coming off injury-plagued seasons and increasingly look like they belong to the realm of good-but-not-great.

Which leaves Wentz, and Goff, and perhaps the Cowboys’ Dak Prescott, along with Mahomes and Mayfield and Watson as the leading candidates to join Ryan and Wilson in an attempt to replicate what Brady, Brees, Roethlisberger, Rivers, Rodgers and, arguably, Manning have accomplished since they all joined the league in a six-year stretch between 2000-05.

Just as big of a question is who will replace those five — and the other pretenders and stopgaps — in the coming seasons. Of the 17 quarterbacks drafted in the first round between 2009 and 2014, Stafford and Newton are the only ones who will enter 2019 with a starting job. Eight of those quarterbacks are out of the league entirely (Mark Sanchez, Josh Freeman, Tim Tebow, Sam Bradford, Christian Ponder, Jake Locker, Luck, Johnny Manziel).

As for the most recent draftees, three of the four members of last year’s class finished as the three lowest-rated passers in the NFL. Josh Rosen has already been traded. Josh Allen still can’t consistently deliver a ball to where it can be caught. Sam Darnold has plenty of advocates, but, well, we’ll see. Lots of people thought Mariota was a franchise quarterback, too (many of whom also think Kyler Murray is one). Wouldn’t it be ironic if Daniel Jones ends up being the one we are still talking about a decade from now (along with Mahomes and Mayfield and 2021′s Trevor Lawrence)?

Whatever the case, the Eagles put themselves on the right side of the curve by making an aggressive move to nab Wentz. Now, the top organizational priority needs to be keeping him healthy. For the good of the team. And, by extension, for the good of the sport.