Brent's bond was set at $500,000 in Irving, Texas., Sunday just before the Cowboys' game with the Cincinnati Bengals in Ohio, The Dallas Morning News reported.
"Jerry Brown was my very best friend and I'm just trying to deal with his death right now," Brent said when he was leaving jail.
Police said Brent was driving his car that crashed in Irving early Saturday, killing practice squad linebacker Brown, 25, who was living with Brent and a friend. Brent and Brown were teammates at the University of Illinois.
Brent's attorney, George Milner, said the bond was "17 times the amount it should be. ... $500,000 is what you get on a capital murder case."
Milner said Brent needs medical attention.
An Irving police affidavit indicated officers used a mandatory procedure to test blood alcohol level after Brent refused.
The arrest warrant affidavit said police noticed an "odor of alcohol emitting from his [Brent's] breath."
Brent is under contract through 2013
Brown joined the Cowboys' practice squad on Oct. 24 after he was cut from the Indianapolis Colts' practice squad.
He had previously played in the Arena Football League and the Canadian Football League.