If healthy, one of the greatest quarterbacks of this generation will have plenty of suitors and perhaps a shot at another championship.
If not healthy, he'll either slightly taint our memories of him with a couple of subpar seasons for a mediocre team or immediately end up in somebody's broadcasting booth (preferably ESPN's).
For 22-year-old Andrew Luck, it's important that he looks at the entire situation unfolding in Indy. While he's undoubtedly excited to have his dreams come true, Luck should be careful to learn the most important lesson for a young athlete: Have a Plan B.
In 2010 Manning threw for an NFL-record 450 completions (since eclipsed by Drew Brees) and a career-high 4,700 yards. The season before that, he won his fourth MVP and a trip to the Super Bowl. A year later, after missing an entire season because of injury, he'll likely be cut and looking for work or something else to do at only 35 -- old in sports but so, so young in life. And get this: Manning's career is the best-case scenario among athletes.
Last year during the NFL lockout, the league and the players' union were arguing over the true average length of a player's career. The union said it was 3.5 years, while the NFL claimed it was six and that for first-round draft picks, the average was close to nine. Whether it's 3.5 or nine, one thing is clear-- in the big scheme of things, pro athletes are not pro athletes for very long.
Even if an athlete retires as the greatest of all time, he or she will still need a post-career plan -- and it's not just about being able to make a living, though money is important. Sports Illustrated found 78 percent of NFL players are flirting with bankruptcy or financial problems within two years of their retirement, and 60 percent of NBA players are broke within five.
But even if sound financial investments are made, and cash flow isn't a problem, Luck and RG3 and all the other young men entering April's draft need to figure out how to live their lives after sports, and they should do that long before they retire.
"You never really have the opportunity to grow up," former Minnesota Viking Alan Page said in the book, "Racing the Sunset: An Athlete's Quest for Life After Sport." "It's like you're living in a candy store and nobody tells you that you'll ruin your appetite."
Page, 66, earned his bachelor's degree in 1967 and in 1978 earned his law degree while still playing. Today he is an associate justice on the Minnesota Supreme Court and a member of the Pro Football Hall of Fame. True, he's a bit of an overachiever, but the point is that he didn't wait until he hung up his cleats to think and plan for the next phase of his life.
Contrast that with the experience of Denise Lewis. The British heptathlete was a gold medalist at the 2000 Olympics, but injuries forced her to withdraw mid-competition in the 2004 games, and she admits a level of depression after retiring at just 32.
"It was like an emptiness," she said. "Luckily the London 2012 Olympics bid came at the same time and I've been involved with that. It's given me a new lease of life."
We tend to stress to young athletes their need to have a backup plan in case they don't make it to the pros, and justifiably so. For most of the young men who enjoyed being part of this month's college football signing day, that will be as close to the NFL draft as they're going to get. Only 1 in 1,000 high school players make it to the pros. We have all seen the depressing stories of talented young athletes who put all their eggs in the pro sports basket, and -- when things don't quite work out -- are lost. The Marcus Dupree 30 for 30 documentary "The Best That Never Was" comes to mind.
But hell, we've seen athletes make it to the pros, be on top of the world and still end up on the losing end of a "Behind the Music" segment.
Just this week we learned that Allen Iverson is broke and trying to find a minor league basketball team to play on because basketball is the only way he knows how to make a living. Even without the money issue, here's what's sadder: Iverson's only 36 years old and it's clear he has no idea what he is going to do with himself for the next 30 years.
He's missing the Plan B I'm speaking of.
Finances are only part of the discussion.
I hope that Luck or Blake Griffin or Cam Newton or presumably Jeremy Lin don't burn through their entire fortune the way Iverson did. And I'm not sure what Manning is going to do next, now that his playing days are just about done, but he strikes me as the kind of person who has a Plan B.
If Luck really wants to be the next Peyton Manning, he should be thinking of having the same.
LZ Granderson is a senior writer for ESPN The Magazine and a regular contributor to ESPN.com. He can be reached at email@example.com.