NFL linebacker Carl Nassib signed a four-year, $3.6 million contract with the Cleveland Browns when he was drafted in 2016. The deal also came with a six-figure bonus: $889,752.

His new salary "didn't really change my headspace much," he tells CNBC Make It. "I was just like, I have this money, I better be smart with it. I was more focused on my career as a football player than worrying about how much money I had in the bank."

Three years after signing with the Browns, Nassib is making a base salary of $2.03 million with the Tampa Bay Buccaneers — and he still plays it safe with his money. The 26-year-old team captain sticks to a monthly budget of $3,500 for rent, food and bills. He spends another $400 to $500 on miscellaneous expenses.

"This year I've been more on top of my budget than ever," he says. That's partly because he hasn't switched teams and had to move to a different city, which is common in the NFL: "My expenses are at an all time low because you don't realize how much moving costs. Everything adds up."