ESPN president John Skipper shocked the sports media world in December by announcing his sudden resignation, citing a "substance addiction" that went back many years.

The surprise move caused sports media observers to scratch their heads, especially considering ESPN had recently signed a contract extension with Skipper through 2021. Just five days before his abrupt departure, he presided over an all-hands meeting at ESPN's headquarters in Bristol, Conn.

But in a new interview with the Hollywood Reporter published Thursday morning, Skipper revealed that he decided to leave the network after a drug dealer who sold the ESPN boss cocaine attempted to extort him.

"In December, someone from whom I bought cocaine attempted to extort me," Skipper told James Andrew Miller, the author of Those Guys Have All the Fun, Inside the World of ESPN. Skipper, who is in rehab, said he was normally careful from whom he purchased cocaine, but decided in December to buy drugs from a dealer he'd never dealt with.

"They threatened me, and I understood immediately that threat put me and my family at risk, and this exposure would put my professional life at risk as well," Skipper said. "I acted very foolishly."

The former ESPN chief said he responded to the threat by revealing his cocaine addiction first to his family, then to Disney chairman and CEO Bob Iger, who agreed with Skipper that it would be best if he resigned.

Skipper called the weekend he wrote his resignation letter "agonizing." After the resignation was formally announced the following Monday, he spent most of the day alone in New York City, the former ESPN boss said.

"I cry sentimentally at movies, but I never cry personally. That's the only day that I cried," Skipper said. "And I cried because I realized the profundity of what I'd done to myself, to my family, and that I'd given up the best job in sports on the planet."

Earlier this month, ESPN named Jim Pitaro, who previously served as Disney's chairman of consumer products and interactive media, as Skipper's replacement. Skipper told Miller that Pitaro is a "good, smart executive" whose style will work at the network, but admitted seeing his replacement named was difficult to swallow.

"I wish him well, and (laughs) I hope he does better than the last guy!" Skipper said.

Read Miller's full interview with Skipper here.