Underwood was born in Philadelphia on March 29, 1977, the youngest child of Paul, a former insurance salesman, and Eileen, an information specialist at IBM.
The family would move to upstate New York, and later to his father's hometown of Fayetteville, North Carolina, after Eileen was laid off from her job.
Underwood accepted a football scholarship from Michigan State University, to play under head coach Nick Saban.
[1] Underwood was selected by the Minnesota Vikings in the first round (29th overall) of the 1999 NFL draft, after his stock rose with his pre-draft workouts.
On August 13, he was waived and forfeited a $1.75 million bonus saying he could not resolve the conflict between playing football and serving his Christian faith.
Multiple times during team meetings, Underwood was found not taking notes, but instead writing about the apocalypse.
[6] On March 10, 2000, he signed a two-year contract with the Dallas Cowboys, who took a chance on him because of the earlier success the team had with Alonzo Spellman, who also suffered from bipolar disorder.
Starting in 2002, he served stints in the Dallas County Jail for aggravated robbery on a paraplegic driver, assault on a police officer, and evading arrest.
In February 2003, Underwood was transferred from Lew Sterrett Justice Center to the North Texas State Hospital in Vernon.
[12] In a September 28, 2010 article, Yahoo Sports noted Underwood's mental health issues as a case in point in regard to the NFL falling short in helping players who suffer from various mental illnesses that are in no small part connected to the pressures of the job of an NFL athlete.