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If you want to make a Philadelphia sports fan groan, mention just about any of the city's sports legends: Donovan McNabb, Allen Iverson, Charles Barkley, Eric Lindros, etc.

If the Eagles are not careful, Carson Wentz will someday be added to the list.

McNabb and the others (and there are enough others to fill a book) were great players. Some were league MVPs. A few were Hall of Famers. The City of Brotherly Love chewed them up and spat them out like wads of stale bubble gum. Mention their names at some Greater Philly sports bar nowadays, and you won't hear about dazzling plays or unforgettable seasons. You'll hear about puking at the Super Bowl, "practice," decades-old dramas and real or imagined shortcomings.

Winning one of Philadelphia's rare championships doesn't help. Philly fans spent the last five years of Ryan Howard's career acting as if his enormous salary came straight from their paychecks. Mike Schmidt ended a century-long World Series drought in 1980 and had to take the field in disguise a few years later.

Philly sports honeymoons are shorter than flight layovers. The moment a young superstar is anointed the savior of the franchise (especially if given a contract to match), he becomes a marked man. Invitations to the execution are printed up during the coronation. Every pebble of discontent or disappointment is the potential start of an avalanche that buries a player's legacy.

Which brings us back to Wentz and the Eagles.

Sunday's putrid loss to the Cowboys threw both the organization and the fanbase into a state of moderate panic. Hours after the game, the Eagles released some back-of-the-roster veterans in what looked like "statement" dismissals. Offensive lineman Lane Johnson grumbled about players arriving late for meetings. ESPN's Josina Anderson reported some anonymous locker room criticism of Wentz before the loss. A notorious local radio pot-stirrer implicated Alshon Jeffery as the source. And beat reporter Jeff McLane asked head coach Doug Pederson about it directly at an early-week press conference. Everyone responded by protesting everything too much.

The Eagles, so calm and collected in both the heat of a Super Bowl run and the eye of a sociopolitical maelstrom two seasons ago, suddenly appear rife with discord and tension. They also look like week-old roadkill on the field. And in the middle of it all is Wentz, seven weeks into a four-year, $128 million contract.

He's playing pretty well, but not great—not as well he's being compensated to play, not as well as that guy in Dallas. And he certainly isn't to blame for the Eagles' discouraging start, except maybe a little bit, or perhaps a lot, because the Eagles are supposed to be his team.

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Wentz, as you no doubt recall, did not lead the Eagles to victory in Super Bowl LII; Nick Foles did that. Wentz did not rally the team with three December wins to get back to the playoffs last year; Foles did that, too, in relief of the oft-injured starter.

When Malcolm Jenkins, the designated voice of reason for the locker room (if not the United States), was asked Tuesday how the team turned things around last year, he began by saying (per Zack Rosenblatt of NJ.com): "I think we had real change on both sides of the ball. You had Nick Foles coming in and obviously that changed a lot of what we did offensively..."

Jenkins then spoke at length about defensive changes, and he later fired back on Twitter at anyone who thinks he blames the Eagles' issues on "one person." It takes a bit of reading between the lines to interpret his statement as shade toward Wentz, but Philly fans read between the lines at a postgraduate comprehension level.

It's silly to suggest that Foles, currently injured and being upstaged in Jacksonville by a bit character from Stranger Things, is a better player or long-term option than Wentz, or that either quarterback could fix the Eagles' myriad problems on defense. But the Eagles are reeling and starting to point fingers. There appears to be a leadership void that Wentz has not yet demonstrated he can fill. And that's how the saga of the downfall of so many Philly sports superstars begin.

The last four days in Philly felt like Terrell Owens' driveway workout of 2005; that was the moment of no return for the McNabb-Andy Reid Eagles, a team that looked like it had all the answers until the fourth quarter of Super Bowl XXXIX six months earlier. There are dashes and pinches of the premature declines of Howard, Lindros and others simmering in the stew as well. Too expensive. Can't stay healthy. Not a leader. We played better with the other guy. Remember him? He was a Philly kind of guy. He had a big (wait for it) heart.

These squalls never blow over in Philly. They grow into monsoons. The Philadelphia mediascape is harsher than even New York's. (I've had my toes dipped in both for enough years to know.) It's more focused, especially on the Eagles; more confrontational and mischievous; more central to the lives and opinions of fans. As for the fans, they (we) are scornful lovers who always dredge up last week's quarrel as ammunition for this week's argument.

Angry fans and ornery sports talk guys shouldn't have any impact on the team or players, but in the City of Burner Accounts, where taking away a player's captaincy is a Scarlet Letter-like public spectacle, where sources don't stay anonymous and radio stations sponsor bus trips to boo draft picks, they invariably do.

After the milk sours for a Philly superstar, it lingers in the fridge for years. McNabb lost the popular vote forever in 2005, but he was still leading (sometimes successful) Eagles teams in 2009 while the home fans wished he would go away. Nearly all of the Randall Cunningham highlights you see on sizzle reels come from 1988-90, not the five years of injuries, benchings and nonstop (often justified) criticism that followed. Iverson delivered his "talkin' bout practice" soliloquy in 2002 but was still on a Sixers team going nowhere until 2006. Howard was earning $25 million to bat .196 in 2016, when the Phillies' World Series glory was ancient history.

And as every time traveler knows, just because you have seen the future doesn't mean you can prevent it. The Eagles could buy or sell at next week's trade deadline, fire coordinators, hold closed-door meetings or whisper more criticism down the lane, and any of it might cause the crisis they are trying to avoid.

So, that's it? Should the Eagles try to bring back Foles? Trade Wentz to the Bengals for a 2020 draft pick? Those are catchy message-board pronouncements that don't reflect reality. Wentz will remain the Eagles' quarterback for years to come, no matter what. He possesses all of the attributes and intangibles of a franchise quarterback. For all of their flaws, the Eagles are a DeSean Jackson injury and some Nelson Agholor miscues away from a 5-2 or 4-3 record and a totally different conversation.

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Philly doesn't love to hate all of its sports legends. There's a small pantheon of beloved tough guys like Brian Dawkins and the Broad Street Bullies, transcendent figures like Julius Erving, a few lovable misfits and some tragic figures. There's no quarterback in that pantheon. Wentz could be the one who fills that void.

Some tough losses and one miserable game do not change that. But throughout Philly sports history, nearly every beginning has been the beginning of the end.

The Eagles changed Philly sports history two years ago. They must now hope that their power to keep doing so didn't skip town for Jacksonville.

Mike Tanier covers the NFL for Bleacher Report. He's also the author of The Philly Fan's Code and other fine books.