O.J. Simpson, who is serving a 33-year sentence in prison, is allegedly undergoing medical tests for a cancerous brain tumor and has asked President Obama for a pardon so he can live out his remaining days at his home.

According to national media outlet, the former football legend experienced severe symptoms of diabetes a few months before that put his life at serious risk.

O.J. Simpson, 66, was found guilty of kidnapping, assault and robbery in 2008 and is set to serve 33 years in the Nevada prison.

"O.J. says his memory is slipping and he gets painful headaches and other symptoms," a source close to Simpson told The National Enquirer in an interview. The former football star listed several concerns related to his condition, including blurry vision, unusual bursts of anger, fits of depression, occasional stuttering, confusion and hearing problems.

The source added that O.J. Simpson had put off physicians for several weeks after the first of his symptoms started surfacing, explaining that the former football player was "afraid of what they would find."

Physicians in the Nevada prison have reportedly confirmed Simpson's brain tumor after the football legend underwent several tests including CT scans and MRIs.

According to a national newspaper, O.J. Simpson had recently agreed to receive the necessary tests for diagnosis and became convinced that he does not have long to live. Simpson reportedly told a close friend about his condition, saying "I feel the end coming. But I don't want to die in prison like common jailhouse scum."

Reports claim that Simpson had attempted to appeal to President Barack Obama for early release so that he can pass away in peace in his home.

Simpson still has another four years to serve at the Lovelock Correctional Center before he can become eligible for parole.