With a monthly full-money extra, I'm Chris Hill, where just a few days away from Superbowl 54,

and while the business of professional football is financially strong, the NFL has had some

high-profile retirements over the past year.

All-proteilants like Rob Grunkowski from the Patriots, Andrew Luck from the Colts, and

Luke Keekley from the Carolina Panthers have all walked away from the game.

What striking is not only the accolades they earned for their talents on the field, it's

the fact that they retired before they turned 30 years old.

Their careers were longer than that of the average guy in the NFL, but these three were

at or near the peak of their powers.

People in and around the league were stunned by these early retirements, but nearly a decade

ago, best-selling author Michael Lewis saw this coming.

He's no stranger to the world of sports.

He highlighted the importance of offensive linemen in his book The Blind Side, and he

spent time with the Oakland Athletics doing research for a book that would introduce a new

term to the world of both sports and business.

Moneyball

Michael Lewis has built his career in part on his interest in topics that are not getting

a lot of attention.

And when I talked with him back in 2011, the health of NFL players was just starting to

become a mainstream topic.

Concussions are becoming more and more of an issue for the NFL.

Do you think the risk of head injuries and concussions is going to change the way professional

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