Brent has been moved to the Reserve/Retired List, Nick Eatman of dallascowboys.com announces. Brent is only 27, so it's not like he's grown out of the game. There's no shortage to the personal problems Brent had to deal with off the field, so he might be leaving the game to get his life in order. Rolando McClain once dealt with a similar situation then later returned, so it's not 100 percent we've seen the last of Brent in the NFL.