O.J. Simpson CTE, O.J. Has CTE

© Joseph Villarin/AP

O.J Simpson's Life Behind Bars: 'He's A Broken Man,' Says Former Business Manager - O.J. Simpson has spent the past eight years locked up in Nevada's Lovelock Correctional Center for his role in the 2007 armed robbery and kidnapping of a Las Vegas sports memorabilia dealer.

He is not fairing well, his former business manager, Nick Pardo, tells PEOPLE exclusively.

"He's a broken man," says Pardo. "He's really becoming a recluse and doesn't want to talk to anybody, including his own family."

Adds Pardo, "He just wants to serve his time and part of him knows the only way to do that is to forget the outside world exists, which is hard to do when the outside world comes to visit you and tells you how they just went to the beach."

Pardo's description of the 68-year-old former football superstar marks a contrast to his image as a chiseled athlete, actor and TV pitchman in the days before his 1994 arrest for the murder of Nicole Brown Simpson and Ron Goldman, for which he was later acquitted.

"He weighs at least 300 pounds and suffers from diabetes," Pardo says. "He got new knees before he went into prison, but the extra weight is hurting him because his knees weren't made to hold that. He needs to lose weight."