The Definitive Guide to Business

Jets player Brandon Marshall shares the biggest business lesson he's learned

Having been in the NFL for a decade, Jets receiver Brandon Marshall knows practically everything about professional football. But he is the first to admit that when it comes to the game of business, he still has a lot to learn.

"I've got to be honest: I'm still young, I don't know it all, but I'm searching," Marshall said on CNBC's "Power Lunch" on Friday.

The 32-year-old Marshall is working with trainer Matt Gates on expanding Fit Speed Athletic Performance, a company that offers training for athletes ranging from children to off-season pros and prospective NFL players.

"The No. 1 thing I've learned is to surround myself with people who are smarter than me." -Brandon Marshall, NFL player and entrepreneur

Marshall shared how watching CNBC's "The Profit," in which entrepreneur and investor Marcus Lemonis tries to rescue failing businesses, got him interested in learning new business tactics.

"There's always something you could get better at," Marshall said.

Brandon Marshall
Scott Mlyn | CNBC
Brandon Marshall

The athlete and entrepreneur has recently taken business courses at Harvard in an effort to learn more.

"The No. 1 thing I've learned is to surround myself with people who are smarter than me," Marshall said.

His approach to business echoes that of Russell Simmons, the entrepreneur who founded Def Jam Records. Simmons said the key to success is being the dumbest person in the room.

"You put your head down and you work very hard until you attract the right people," Simmons said. "I am very lucky that, over time, I am able to find people to help build out the ideas that I have — people who are smarter than me to help deliver on the promises."