Among the other revelations in Sweetness: The Enigmatic Life of Walter Payton, which Sports Illustrated is excerpting in this week's issue, author Jeff Pearlman (a former SI senior writer and current contributor to SI.com) says Payton frantically juggled his wife and girlfriend during his Hall of Fame weekend in Canton in July 1993.

Pearlman said he interviewed 678 people for the book, which he worked on for 2 ½ years. Sweetness chronicles Payton's life, from his childhood in segregated Mississippi, to his college years at Jackson State, to his 13-year NFL career and his post-Bears life. Payton had primary sclerosing cholangitis, a rare and deadly liver disease, and died in 1999 from bile duct cancer. (The painkiller Darvon, which was first approved in the 1950s, is an opioid narcotic used to treat mild to moderate pain. It has since been pulled by the market.)

In the book, Pearlman writes:

The burden of loneliness and his marriage weren't Payton's only problems. As a player he had numbed his maladies with pills and liquids, usually supplied by the Bears. Payton popped Darvon robotically during his playing days, says [his longtime agent Bud] Holmes, "I'd see him walk out of the locker room with jars of painkillers, and he'd eat them like they were a snack", and also lathered his body with dimethyl sulfoxide, a topical analgesic commonly used to treat horses. Now that he was retired, the self-medicating only intensified. Payton habitually ingested a cocktail of Tylenol and Vicodin. In a particularly embarrassing episode, in 1988, Payton visited a handful of dental offices, complaining of severe tooth pain. He received several prescriptions for morphine and hit up a handful of drugstores to have them filled. When one of the pharmacists noticed the activity, he contacted the police, who arrived at Payton's house and discussed the situation. Payton was merely issued a warning. "Walter was pounding his body with medication," says Holmes. "I wish I knew how bad it was, but at the time I really didn't."

READ THE EXCERPT FROM SPORTS ILLUSTRATEDA Q&A WITH AUTHOR JEFF PEARLMANGALLERY: RARE PHOTOS OF WALTER PAYTON

The book reports that Payton often used nitrous oxide while he was playing and after he retired. Pearlman writes:

Back when Payton drove his own RV to Bears training camp, he used to load the rear of the vehicle with tanks of nitrous oxide, commonly known as laughing gas. At nights and during breaks in the action, players sneaked into Payton's trailer, loaded the nitrous oxide into balloons, then carried them around while taking hits. The goofy laughter could be heard throughout the training facility.

Now retired, Payton turned to nitrous oxide more than ever. Large tanks occupied a corner of his garage, and he held a gas-filled balloon throughout portions of the day, taking joyous hits when the impulse struck.

The book says that Payton wrote to a friend that he contemplated suicide in his post-football career. Here is another passage from the excerpt:

On one particularly dark day in the mid-'90s, Payton wrote a friend a letter saying that Payton needed to get his life in order and was afraid of doing "something" he'd regret. In the note Payton admitted that he regularly contemplated suicide. Thinking about "the people I put into this f---ed-up situation," he wrote, "maybe it would be better if I just disappear." Payton said he imagined picking up his gun, murdering those around him, then turning the weapon on himself. "Every day something like this comes into my head," he wrote. He was distraught over these persistent thoughts about wanting to "hurt so many others" and not thinking "it is wrong." Payton ended the letter by admitting that he needed help but that he had nowhere to turn.

As for Payton's 23-year marriage to Connie, Pearlman says that "it was a union solely in name."

From the excerpt:

Walter's extramarital dalliances were becoming common knowledge throughout Chicago. He confided in those with whom he was close that when his children graduated from high school, he would divorce Connie [who declined to speak at length to the author] once and for all. "He didn't want the children to go through the rigors of a celebrity divorce," says Kimm Tucker, the executive director of Payton's charitable foundation. "He knew what the spotlight felt like when it was negative, and he hated the idea of Jarrett and Brittney experiencing any of that." Says his longtime friend Ron Atlas, "Walter knew that if he left Connie, all the work he'd done to his image would go by the wayside."

Shortly after he learned he'd been voted into the Hall of Fame, Payton spoke with Lita Gonzalez [not her real name], a New Jersey-based flight attendant with whom he'd been in a tempestuous relationship since they'd met at the Michael Spinks-Mike Tyson heavyweight title fight in Atlantic City in 1988. "I'm coming to the ceremony," Gonzalez said. "There's no way I'd miss it." The last thing Payton needed was to have his Hall of Fame weekend complicated and compromised. But Lita was coming, and she expected to be treated as his girlfriend. "She was insisting she be seated in the front row," says Tucker. "We said, 'Lita, are you insane? We're marketing this man as a family-friendly spokesperson. His whole image is based around decency. You will ruin him.

Pearlman said he wanted to write a book about "someone decent; about someone caring" following his Roger Clemens biography. "Walter Payton was insanely curious, and his interest in other people -- regular fans, folks on the street -- extended beyond the scope of nearly any athlete I've ever come across (Sean Casey the possible exception)," Pearlman said. "Best of all, Payton had depth. There was so much beneath the surface with this man. But that was also a problem. Because for all of his depth, Payton spent his life as a lockbox. He trusted very few people, and confided in -- at most -- three or four. The image out there when he played is the same one out there today: Classy guy, perfect in all areas, the ultimate role model, great running back and the ultimate prankster. And while that is, in many ways, sort of true, it's also a cheap, easy and unfair portrait."

Asked if he worried about facing a backlash for tarnishing the image of a deceased man, Pearlman said, "I sure do. It hurts me that this will hurt his kids. It really does because Jarrett and Brittney are wonderful, engaging, fun, caring people and they're really uplifting figures in the Chicago landscape ... That said, I set out to write a definitive biography -- period. When people would ask, 'Well, is this going to be positive?' I'd say, 'Not positive, not negative -- definitive.'"