Brent, a defensive tackle for the Dallas Cowboys, was at the wheel of a car that crashed last December. Jerry Brown, a good friend of Brent's and a member of the Dallas practice squad at the time, was killed in the wreck.
"This is the right decision for me and something that I have given a lot of thought to," Brent said in a statement released by the Cowboys. "I am at a point where my main focus is all about getting the priorities in my life in order.
"Those priorities are more important than football. Doing the right things in life are more important than football. I love the game very much. I love my teammates, but this is the right thing for me to do."
Brent started five games for Dallas at nose tackle last season. He was chosen in the 2010 supplemental draft out of Illinois.