NFL fans remember Tiki Barber for his ten-season career with the New York Giants, but entrepreneurs can learn a lesson in resiliency from his up and down journey off the field, which eventually landed Barber, 42, at the top of a startup that's raised $22.6 million to date.

After taking his final handoff at the Pro Bowl in 2007, Barber looked to real estate to kick off his post-NFL career. Barber linked up with Miami Dolphins owner and real estate mogul Stephen Ross, chairman and founder of Related Companies, to pursue an affordable housing deal in Barber's hometown in Virginia. Unfortunately for Barber, who was just getting his feet wet in the business world following a successful football career, 2007 proved to be an unfortunate time to take on this type of project.

"It happened right around the correction in 2008, so tax credit equity went from 96 or 97 cents on the dollar to about 67 cents on the dollar, so we weren't able to finance a lot of the deal on the equity side," said Barber. "[Ross] ended up letting us out of that deal because we were going to default, and it saved us from some serious liability."

Barber recalls that Ross, a veteran in the real estate world, was able to stay in the deal and turn things around because "Steve Ross is Steve Ross." For Barber, it was a learning experience and an opportunity to move on to a new challenge.

Barber's next career move brought him back into the world of sports. Working for NBC, he contributed to the Today Show, NBC Sports and Football Night in America as an on-air personality.

His first stint in broadcast ended in 2010 when NBC did not renew his contract, and at the same time he was going through a very public divorce. "It rocked my life, my existence," said Barber. "I wasn't doing media anymore, I didn't have a business, and I was just kind of--I don't know--lost."

At this low point in his life, Barber said two things happened that helped to lift him out of his slump. First, he joined the CBS Sports Network as a radio host. Next, an important figure from his past reached out to reconnect.

Rick Gerson, a former classmate of Barber's from the University of Virginia, invited Barber to have lunch with his brother, Mark Gerson, founder of the Gerson Lehrman Group. When the two sat down for lunch, followed by a cigar, they began talking about the issues that former athletes often face.

"We ended up generating this idea of creating a marketplace where athletes could engage with the public," said Barber. "And so we created Thuzio."

Thuzio, stemming from the word "enthusiast", initially began as a talent broker business, and Barber pointed out that this was a few years before the concept of influencer marketing gained mainstream recognition. Barber and Gerson built a business providing athletes the opportunity to accept paid appearances ranging from bar mitzvahs to corporate speaking engagements.

While their initial model served its purpose, helping them network with movers and shakers in the corporate world, Barber said he came to this important realization: "You can't build a scalable business without reoccurring revenue."

The business model has since shifted away from one-off events towards steadily engaging corporate clients including Bank of America, Merrill Lynch and JP Morgan. It has also split into two companies, with their talent database and technology platform operating as Julius, and the other entity operating as the Thuzio Executive Club, a paid membership program that provides access to exclusive events where executives can rub shoulders with athletes and celebrities.

"It was really a drastic shift, if you dig into what Thuzio has become," said Barber. "It was hard, but it was meaningful, and it was useful because it allowed us to scale."

Throughout his journey, Barber said he has learned that "Success is about relationships. And if you get too disconnected, those relationships never form." And from his story, it's clear that the relationships Barber has cultivated since his initial post-NFL slump, along with his drive to succeed, have helped his career bounce back in a big way.