Brown spent his first seven NFL seasons with the 49ers and regularly squared off against the two wide receivers during practices when hitting was kept to a minimum and the competition light.
This time there won't be any restrictions, and Brown is looking forward to it.
''I'll have the opposite jersey so it won't be practice, that's the biggest thing,'' Brown said. ''It'll be exciting. They'll be hyped up to play against me, I'll be hyped up to play against them. It's always great competition when you go against guys you're familiar with.''
Brown has already exchanged a few friendly phone calls with some of his former teammates across the bay, but the love almost assuredly wasn't shared with San Francisco's front office.
A fifth-round pick in 2007 who started 42 games over his final three seasons with the 49ers, Brown didn't exactly part on amicable terms. He was offered a three-year contract to stay in San Francisco - which Brown termed a ''slap in the face'' - and eventually signed a $3.5 million, one-year deal with Oakland.
He hasn't looked back since, even as the losses pile up for his current team.
The Raiders limp into the game at 1-11 and steaming toward the No. 1 overall pick in next year's draft. The 49ers (7-5) have also had their share of stumbles this season but still cling to playoff hopes.
''I wouldn't change it,'' Brown said. ''Once you sign up for something, man, you gotta finish it. I'm that type of guy where when I sign up for something I'm going to give you everything I have until the end. I'm still jacked up about signing here. I love the guys, I love the locker room, I love the organization. We just don't have the wins that we feel like we should have.''
Brown signed with the Raiders along with former San Francisco teammate Carlos Rogers to help improve Oakland's secondary. It hasn't worked out as hoped.
Oakland is ranked ninth in pass defense but the Raiders have only forced eight turnovers - tied with the New York Jets for fewest in the NFL - and have only five interceptions.
Rogers started the first seven games before being placed on injured reserve last week with a knee injury.
Brown, who has been limited this week in practice with a minor foot injury, has been one of Oakland's few consistent players. He has 52 tackles and is only seven shy of his career high. Along with safety Charles Woodson, Brown has also served as mentor and tutor to some of the team's younger defensive backs.
''The guy goes out there and he gives you a solid day's work every single day out there in practice, and that's important,'' interim Oakland coach Tony Sparano said. ''He really is a good pro, a good guy to sit and visit with when you're just talking about your football team a little bit and you want to pick somebody's brain.''
The Raiders undoubtedly sought out Brown to get some insight on Boldin, Crabtree and the rest of the 49ers offense.
''When you think of the Bay Area, you think of both teams,'' Brown said. ''It's going to be a physical matchup. It's going to be electric out there. The atmosphere will be great. But besides all of that, you just have to go out and play football and let the chips fall where they'll fall.''
Notes: Sparano said the team has yet to decide whether to add WR Rod Streater to the 53-man roster. Streater was on the injured reserve list with a designation to return. He's been practicing the past two weeks but has yet to play. ... RT Menelik Watson (ankle/foot), TE Brian Leonhardt (concussion) and S Jonathan Dowling (back) did not practice. ... LB Sio Moore (hip) and CB Neiko Thorpe (hand) were limited.