Walker, a running back, chose to skip his senior year at Notre Dame and enter the NFL draft earlier this year.
He was not drafted but hooked up with Houston as a walk-on.
He was released on Friday, according to a posting on the team's Web site, one day after the Texans' final pre-season game and one day before NFL teams must reduce their roster to the opening day 53 players.
http://accesswdun.com/article/2007/9/86273