It's a tragic tale that has played out with too many former NFL stars: A player earns a fortune during a successful pro career only to find himself struggling financially a short time later.
Former NFL quarterback Vince Young, who made millions during his playing years, recently filed for bankruptcy protection, according to reports last week in The Wall Street Journal and elsewhere. And he's just the latest former player with money troubles.
"You have a lot of situations where players set up a lifestyle that's not really sustainable," said Muhsin "Moose" Muhammad, a former wide receiver who appeared in two Super Bowls, with the Carolina Panthers and Chicago Bears. "You have to have enough restraint, and you have to be disciplined enough to only think about what you need, as opposed to what you want."
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According to the NFL Players Association, the average NFL career lasts just over three years and translates into average career earnings of about $4 million after taxes.
But many players find that's not enough to cover their spending habits.
Winfred Tubbs, a Pro Bowler who played seven seasons with the New Orleans Saints and San Francisco 49ers, said many players don't have the required financial discipline.
"The worst thing about athletes is we get rich at a young age—at an age that we're vulnerable, but we feel like we're Superman," he said. "At 23, we're going to make it rain in the club if we're making $50,000 a year or ... $10 million a year. The difference is, the person making $50,000 a year would be using $1 bills, and an NFL player might be using $10 bills."
Now an entrepreneur, Tubbs counts car dealerships, rental properties and an oilfield services company among his continuing post-NFL ventures.
Not all former players demonstrate his business acumen, however, said Tubbs' wealth manager, Ed Butowsky of Chapwood Investments.
"They put too much money in private, illiquid investments, and they do this because they're familiar with this category," he said. "They'll put money into a restaurant or a real estate brokerage."
"Everybody wants a restaurant," said Tubbs. "It's something they can put their name on, that they can own, that they can show people, 'I made it, I own a restaurant.' But they don't know that restaurants are horrible investments."
That type of private venture is almost certain to fail, Butowsky said, adding that "only 1 in 30 of those investments actually work."
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Another common pitfall for NFL players is not knowing where to turn for investment advice.
"There are a lot of people out there who can take advantage of you," said Tubbs. "I've had a couple of bad brokers, and I didn't know that. It took someone else to figure that out."
Former wide receiver Muhammad said that bad brokers looking for easy money from an unsophisticated player sometimes present business ideas that are downright laughable.
" 'Shark Tank' is nothing compared to some of these proposals," he said. "Someone came to me one time to invest in a Michael Jackson statue cologne that would eventually retail on QVC. I said, 'You've gotta be kidding me. I wouldn't invest a dollar in it.' "
"I was lucky that I was born bigger and faster than the average Joe, and play a game that people are stupid enough to pay millions of dollars to watch."
While players can fall prey to poor business schemes, they can also sustain career-ending injuries that simultaneously leave them out of a job and saddled with steep medical expenses.
"The players we've seen that have had challenges are the ones who have had to take care of serious injuries and ... medical bills piling up," said NFLPA spokesman George Atallah.
Football's contract system doesn't provide as much job security as other professional sports in the case of injury, said J.B. Bernstein, CEO of the sports agency Access Group.
"If you're a baseball player, you blow out your knee, and you have five years left on your contract," he said. "In the NFL, if you blow out your knee, you get cut at the end of the year."
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That's exactly what happened to Tubbs.
"I got hurt in my last year," said the former linebacker. "I played on my hurt knee all year. The moment the last game ended, and the MRI showed that the damage was a lot worse than I thought, they cut me. I was 31, 32 years old, and I was forced to retire."
Tubbs said it's a good example of why players need to plan for life beyond the field if they don't want to end up struggling.
"I was lucky that I was born bigger and faster than the average Joe, and play a game that people are stupid enough to pay millions of dollars to watch," he said. "The downfall of that is that it was only temporary."
—By CNBC's Adam Molon. Follow him on Twitter: @CNBCMolon