But Brent wasn't starting on Dallas' defensive line when the Cowboys kicked off in Cincinnati on Sunday. He was in jail, accused of driving drunk and causing a fatal accident that killed Brown, an expectant father who had just landed a spot on the Cowboys practice squad.
About an hour after the grieving Cowboys secured an emotional 20-19 victory over the Bengals on the final play, a barefooted Brent walked slowly out of the jail in the Dallas suburb of Irving after his release on $500,000 bond. Surrounded by camera crews and reporters, Brent had several patches of missing hair and a bandage wrapped about his right hand.
"Jerry Brown was my very best friend, and I'm just trying to deal with his death right now," Brent said, stopping briefly when asked if he had anything to say to Brown's family. He didn't answer any other questions.
Brent, a 6-foot-5, 320-pound nose guard, was arrested at the scene of the accident Saturday on suspicion of driving while intoxicated, a charge upped to intoxication manslaughter after the 25-year-old Brown died.
Attorney George Milner complained that Brent's bond was set "16 times higher than it would have been for anybody that doesn't play for the Dallas Cowboys."
"He is torn up," Milner said. "It's not a good moment for anyone. I'm going to take him home. He needs family around him."
Brown had promised his family that he would play professional football full time, his grandmother said.
"He lived for football," Theresa Clark, 63, of St. Louis, told The Associated Press on Sunday. "He loved it with all his heart."
The two athletes' friendship, which blossomed during their three seasons at the University of Illinois, was obvious to those who knew them. Milner said Brown was living with Brent during the six weeks he spent with the Cowboys.
"You can't get any tighter than those two," Milner said, crossing his index and middle fingers. "It was the closest family he had was Jerry Brown."
The circumstances surrounding Brown's death didn't change his family's view of his relationship with Brent, who pleaded guilty to a driving under the influence charge while a player at Illinois in 2009.
"I'm quite sure that Jerry thought the world of him and respected that young man," Clark said of Brent.
In the Illinois case, Brent was sentenced to 60 days in jail and two years of probation among other sanctions, court records show.
According to a probable cause affidavit released Sunday by Irving police, officers said they detected "a moderate odor of alcohol" from Brent's breath and that he "admitted to consuming alcohol at a club," but wouldn't identify which one. Police said Brent gave a blood sample at the hospital on Saturday.
Brown's mother, Stacey Jackson of Champaign, Ill., confirmed Brown's final Facebook post from Nov. 29, in which he wrote that he was expecting a child and "how the fast life isn't as fun as it use to be after living it for so long."
"She will be here in two more months," Jackson said of Brown's baby daughter. "She is going to be well loved. I have scrapbooks and everything to show her what type of father she had."
Clark saw Brown about four or five months ago, but spoke with him frequently via Facebook.
"I have 20 grandchildren and Jerry is the oldest," Clark said. "They all looked up to him. They praised him. They were all really upset and crying. They are going to miss their big cousin. He was one in a million."
The accident happened hours before Brent was to be on a team flight to Cincinnati. The Bengals held a moment of silence before Sunday's game, and most Cowboys bowed their heads. Dallas quarterback Tony Romo and several other players had their hands over their hearts.
On Fox's NFL Sunday pregame show, Cowboys owner Jerry Jones said the team had focused on Brown's death in the "last few hours." He didn't mention Brent, who played in the first 12 games and was a bigger presence than expected on defense because of injuries to Jay Ratliff.
"First of all we all know, but we remind ourselves that there is something more important than football, and this is life, and certainly the lost life of Jerry," Jones said. "On the other hand, they know the best way they can honor Jerry, because he was such a hard worker, so conscientious and enthusiastic about his career."
The Cowboys didn't hide their emotions after Dan Bailey kicked a field goal as time expired to keep the team's playoff hopes alive.
"I don't remember crying this much other than maybe the day I was born," Dallas defensive end Marcus Spears said. "With Josh's situation and Jerry being gone, you felt it."
Cowboys coach Jason Garrett said after the game that he had called Brown's mother and said the team would be sending her the game ball.
Cowboys spokesman Rich Dalrymple said the team was planning a private memorial service for Tuesday in the Dallas area.
It marked the second straight week the NFL found itself dealing with a tragedy right before game day.
Last Saturday, Kansas City Chiefs linebacker Jovan Belcher fatally shot his girlfriend before killing himself in front of his coach and general manager. The 25-year-old Belcher shot himself in the parking lot at the team's practice complex at Arrowhead Stadium.