Carl Nassib may earn a nice paycheck as a defensive end for the Tampa Bay Buccaneers, but he certainly isn't living the high life.
His rules are simple: Live below his means and put money away for the future by using investments readily available to average Americans.
Younger people "have a much larger time span to invest, so I think with long-term investing, index funds are a great tool," Nassib said Friday on CNBC's "Power Lunch. "
His interest in finance began after he was drafted by the National Football League in 2016. He started his career with the Cleveland Browns and in 2018 started playing for Tampa Bay.
"I didn't want to pay someone to manage my own money, so it took a while, but I educated myself," he said.
Nassib, who has career earnings of $2.73 million according to the website Hero Sports, has a strict monthly budget. During the season, it is $3,500 and covers food, rent and bills. Off season, he has a higher budget of $5,500, because he travels more to see friends and family and no longer has meals provided by the team.
"I try to get at least to where I have $400 or $500 miscellaneous spending, and then everything else is accounted for," Nassib explained.
He's been successful enough that he has taken to giving out financial advice to his teammates. In an episode of the HBO documentary series "Hard Knocks: Training Camp with the Cleveland Browns, " he was seen teaching players about compound interest, which is essentially interest on interest. It's calculated on the initial principal and the accumulated interest over the years.
"This is the easiest equation to make you rich," he said on the show. "It's crazy."
It's an important lesson for anyone, but he likes to stress it to NFL players who may spend too much of their salary and could ultimately wind up broke.
As he likes to point out, they may be in the 1% of earners, but they are not in the 1% of wealthy Americans.
"It's a matter of realizing your spending habits and realizing living below your means," Nassib said. "More and more NFL players are doing that every day."
Disclosure: NBCUniversal and Comcast Ventures are investors in Acorns.
— CNBC's Arielle Shapiro contributed to this report.