Peyton Manning is retiring. He informed the Broncos of his decision on Saturday night, reports CBS Sports NFL Insider Jason La Canfora, and there will be an official announcement on Monday. ESPN's Chris Mortensen first reported the news.

"When you look at everything Peyton has accomplished as a player and person, it’s easy to see how fortunate we’ve been to have him on our team,” executive vice president and general manager John Elway said in a statement. “Peyton was everything that we thought he was and even more -- not only for the football team but in the community. I’m very thankful Peyton chose to play for the Denver Broncos, and I congratulate him on his Hall of Fame career.”

Coach Gary Kubiak added: "It was a blessing to coach Peyton Manning. Nobody worked harder at the game and nobody prepared harder than Peyton. His preparation was the best I’ve ever seen with how he went about his business. There was nothing like his work habits. Each and every week, he did everything he could to get ready to play not only against the defense but even against the coordinator. Being with him this season, going through what we went through and accomplishing what we accomplished -- that was special. He and I battled together and along the way we talked about dreaming that it could end the way it ended. And I’ll be damned, it did."

After 18 seasons, Peyton Manning has called it a career. (USATSI)
After 18 seasons, Peyton Manning has called it a career. (USATSI)

Since the Broncos won Super Bowl 50 last month, there have been weekly reports that Manning was going to call it a career. And now, after 18 seasons, 71,940 regular-season passing yards, 539 touchdowns and two Lombardi Trophies, it's a wrap.

Manning will go down as one of the best players in NFL history, and in just over five years, he'll be in Canton, Ohio giving his Hall of Fame speech.

Details of how the retirement came about, via CBS Sports NFL Insider Jason La Canfora. Manning called team president Joe Ellis,  Elway and Kubiak to let them know his plans, but La Canfora writes that, despite recent media rumblings that Manning might continue his career, the decision was fully expected. His friends, family and agent had all urged him to retire. If Manning hadn't retired, the Broncos were going to release him this week.

Why did Manning retire now? The 2016 season is still six months off. Like most things, it came down to money. If Manning was still on the roster on March 9, the official start of the new league year, his $19 million base salary ($21.5 million cap number) would become fully guaranteed. That's a lot to pay any player, especially a 39-year-old quarterback who had his worse season as a professional in 2015.

In terms of nostalgic parallels, Manning's retirement dovetails nicely with that of Broncos general manager John Elway, who at 38, walked off into the sunset following the Broncos' Super Bowl title following the 1998 season. (One huge difference: Elway ranked 4th among all QBs that season.)

So what are the Broncos going to do in a post-Manning world? The first order of business seems to be re-signing Brock Osweiler, their 2012 second-round pick who started seven games in 2015 while Manning was sidelined with a foot injury. Osweiler was serviceable (170 of 275, 1,967 yards, 10 TDs, 6 INTs), and at 25 the expectation is that he will get better. But the Broncos don't want to pay a good young prospect franchise-quarterback money.

The expectation is that Osweiler will earn a contract that pays him at least $15 million annually (there's reportedly a three-year, $45 million offer on the table), which is in the neighborhood of what young, on-the-rise passers can expect to make, (adjusted for the salary cap).

What won't happen: The Broncos let Osweiler walk; both Elway and coach Gary Kubiak are high on the quarterback.

"I think that with the sample size that we got from Brock, we were excited about what we saw. ... I think he proved a lot to us," Elway said earlier this year.

Kubiak added: "I think he has a bright future. Obviously we think the world of him. We want him to be a part of our football team."

Another reason to learn and grow with Osweiler: That Broncos' defense. It -- not Manning -- is the reason Denver has another Super Bowl title. And it will make life eminently easier for Osweiler as he transitions to the full-time job.

Peyton's legacy... Is probably best told through the eyes of teammates, coaches and opponents.

Tom Brady, following the 2010 season"To me, he's the greatest of all time. What he's accomplished and the way that he studies, the way he prepares. He's really got a killer instinct too. I've been fortunate to be around him on a lot of occasions and we always hit it off; we have a great relationship and he's a friend of mine and someone that I always watch and admire because he always wants to improve, he always wants to get better and he doesn't settle for anything less than the best."

Tom Brady considers Peyton Manning one of the best QBs ever. (USATSI)
Tom Brady considers Peyton Manning one of the best QBs ever. (USATSI)

Former Colts coach Tony Dungy: “He’s probably the hardest-working guy I’ve been around who has great ability. Overachievers work hard because they have to. Peyton has rare talent, but chooses to push himself like he doesn’t.”

Frank Reich, Manning's QB coach in Indianapolis: "His mind is always going, he’s formulating a plan, synthesizing all this information that he is hearing, seeing, studying from other people. He’s listening, but he’s going to call the shots. There might not be another one like him, who does it like he does it."

Former teammate, offensive lineman Adam Meadows: "He lives, eats, breathes, smokes, snorts, chews football. He's just a machine. That's all he wants to do. I think he expects other people to approach it the way he does. It's not always a good thing."

CBS Sports NFL analyst and former NFL QB Rich Gannon: "He's at the Ph.D. level. He anticipates ahead of time based on his film study and preparation during the week. He's able to preview information in the huddle ahead of time. 'Hey, guys, I'm anticipating pressure. Heads up for this.' Then he can get up to the line of scrimmage and recognize the front, the down and distance, the coverage, where the pressure's coming from, and change the protection."

Former teammate, wide receiver Brandon Stokley: "He's the best that's ever played this game as far as quarterbacks are concerned. When he's retired, they'll compare everybody to Peyton Manning, without a doubt."

Peyton's life after football: After 19 seasons, Manning has made enough money to take several lifetimes off. According to Spotrac.com, he's earned nearly a quarter-billion dollars on the football field, and that doesn't include the myriad gigs as corporate spokesperson for just about everything under the sun.

So what will he do with the next chapter of his life? There has been speculation that Manning could move directly into an NFL front office -- the Titans and Browns were mentioned as possible landing spots as recently as November. Manning will also be highly sought after as an NFL television analyst.

And if he chooses to do neither, he can always hawk pizzas and beer -- or focus on his hip-hop career.

Manning knows his way around a camera, both on and off the field. (DirecTV)
Manning knows his way around a camera, both on and off the field. (DirecTV)

Off-field issues. Could a recent spate of off-field issues have hasten Manning's retirement? It's hard to say but the NFL is conducting an investigation into HGH allegations involving Manning. There's also the 14-year-old lawsuit (as part of a 20-year-old case) that resurfaced last month involving Manning and former University of Tennessee trainer Jamie Naughright.

Next stop: Hall of Fame. We could spend thousands of words on Manning's on-field accomplishments, but we'll just leave you with some of the highlights.

1 (of 2) - quarterbacks (along with Brett Favre) to beat all 32 teams.

2 - Super Bowl titles.

4 - Number of times Manning has finished a game with a perfect passer rating.

5 - Associated Press NFL MVP Awards.

5 - Minimum number of touchdown passes Manning has thrown against every team -- including the Broncos and Colts. The Texans (48) have allowed the most.

8 - The number of quarterbacks in league history -- including Mannning -- who have thrown seven touchdowns in a game.

10 - Most seasons with at least 350 completions.

13 - Most consecutive seasons with at least 25 touchdown passes.

14 - Most seasons passing for at least 4,000 yards.

19 - Most games completing at least 80 percent of his passes.

25 - Most games with at least 4 touchdown passes.

45 - Most comeback wins.

55 - Most touchdown passes in a season (2013).

56 - Most game-winning drives.

93 - Most games throwing for at least 300 yards.

200 - Most career wins, including the postseason.

342.3 - Highest average passing yards per game in season (2013).

539 - Most touchdown passes in a career (121 -- or 23 percent -- of those TDs went for at least 30 yards).

5,477 - Most passing yards in a season (2013).

71,940 - Most passing yards in a career.

Manning's first touchdown pass went to Marvin Harrison. His last touchdown pass went to Owen Daniels.

*(stats via PFF, SBNation and the Denver Post)