Peyton Manning walks away with an even more complicated legacy

Peyton Manning will announce his retirement on Monday after 18 NFL seasons. It’s one of the few things we definitively know about him.

If you’re not the biggest Peyton fan — and there are more than a few of you here in New England — you’ll probably want to avoid ESPN, talk radio, and Twitter on Monday. It’s going to be an all-out Peyton Love Fest as the sports media regales us with details of his legendary career.

Manning walks away with most of the important quarterback records — most passing touchdowns (539), most passing yards (71,940), most victories as a starting quarterback (200 regular and postseason), and most MVP awards (five) — and, of course, with two Lombardi Trophies, one each with the Colts and Broncos.

Manning also leaves the game as one of its most celebrated personalities. He implored us with his folksy twang and self-deprecating sense of humor to “cut that meat!” or buy Papa John’s pizza, Nationwide Insurance, or SiriusXM radio. His hosting appearance on “Saturday Night Live” was phenomenal. He might slip into the broadcasting booth as soon as this coming season, and he would probably do well in politics if he ever went that route.

There’s not much to dislike about the Manning that has been pre-packaged and sold to us by the NFL, sports media, corporate America, and the Manning family themselves. His aw-shucks, down-home persona made him America’s Everyman, especially compared to his rival, Tom Brady, who jets across the world with his supermodel wife to sell UGG boots and expensive watches.

But the real Manning legacy is much more complicated on the field and now, suddenly, off of it.

He walks away from the game with a strange cloud overhead. In December, Al Jazeera reported allegations of HGH use. Then last month, a 20-year-old story resurfaced from Manning’s days at Tennessee, where he may or may not have sexually assaulted a female member of the training staff, depending on whose friends and attorneys you believe. He also may or may not have ruined the woman’s reputation after she tried to move on with her life.

Neither story was proven, and now that Manning walks away, the loose ends will probably not be tied up.

Yes, it is a little suspicious that in 2013, two years after Manning missed an entire season because of a career-threatening neck injury that required four surgeries, Manning put together one of the greatest quarterback seasons of all time (5,477 yards, 55 touchdowns and 10 interceptions). But no, he did not fail a drug test (for HGH or any other PEDs), or leave a whisper of evidence of PED use, other than an acknowledgment that his wife had HGH shipped to her in 2011. Now that he’s retiring, the NFL won’t and can’t pursue any sort of punishment against him.

And who knows what to make of the incident at Tennessee? One day, an ex-teammate claims he witnessed the event and that Manning did nothing wrong. The next day, another ex-teammate claims the other teammate is lying.

Did Manning simply “moon” the woman in a harmless prank, or do something much worse? The lawsuit was settled, and doesn’t seem it will progress beyond the he-said, she-said phase.

Is Peyton really a creep? Or is he getting railroaded by lawyers who were upset with the outcome and a media that is desperately looking for any warts on an otherwise spotless off-field record? As upsetting as the Tennessee incident is, there are also countless stories of Manning’s good will off the field, like the way he reached out to a woman dying of breast cancer a few months ago.

Is Peyton genuine? As public of a persona as he has, we don’t know much about him. How many people can pick his wife, Ashley, out of a lineup? How many people know that he is the father to twins born almost five years ago? Remember that hilarious game of keep-away Manning’s teammates played with him after he broke Brett Favre’s record for touchdown passes?

Turns out, it was staged.

Manning’s legacy on the field is no easier to grasp. He doesn’t fit into any simple narratives.

Is he the GOAT — Greatest Of All Time? The stats and the MVPs and the records he holds indicate as such. His 14-13 postseason record suggests otherwise.

Manning did win two Super Bowls, but his second championship was earned in spite of him, not because of him.

Most unbiased observers would place Brady, Joe Montana, and Johnny Unitas ahead of Manning on the list of all-time greats. At best, Manning deserves the fourth spot on Mount Rushmore, although Otto Graham, Roger Staubach, and Dan Marino may take issue with that.

But that second championship also complicates other pre-packaged story lines.

Manning was known as a great regular-season quarterback who choked in the playoffs. Now he retires with a winning postseason record and the accomplishment of being the only quarterback to win a Super Bowl with two franchises.

And Manning was also known as a great quarterback who couldn’t beat his biggest rivals, Brady and Patriots coach Bill Belichick. Manning lost his first six matchups against the two, and retires with a 6-11 overall record against them. But Manning won the last three matchups against Brady and Belichick in the AFC Championship game, including two wins in the last three years.

Manning would have been a first-ballot Hall of Famer based on his 14 seasons with the Colts alone, but his four-year swan song with the Broncos cemented his place as one of the all-time greats.

Manning was supposed to be washed up in 2011. Instead, he compiled record-setting numbers and took his team to two Super Bowls in four years.

But how are we supposed to remember Peyton, on and off the field? The more we saw of Manning in his final years, the more it complicated his legacy, both for better and for worse.

■ Brady congratulates Manning on ‘incredible career’

■ Christopher L. Gasper: If this is it, Manning went out a winner

■ Gasper: Brady and Manning are bonded by history

Ben Volin can be reached at ben.volin@globe.com. Follow him on Twitter@BenVolin.