Bruce Irvin doesn’t have the time or the temperament for trips down memory lane. But this one, the Raiders’ outside linebacker admits, is too good to pass up.

Oakland signed inside linebacker Perry Riley Jr. two weeks ago. He and Irvin had met before.

“Fourth grade,” Irvin says, without a hint of a smile. “We were enemies. We were both the biggest and the fastest in the school. Both trying to be the biggest guy on campus.…

“We were enemies for a good little minute.”

The Friday before he signed with the Raiders, Riley was talking to his mom about which team he wanted to play for. Surprised that he had been cut by Washington, Riley wanted to stay close to his Stone Mountain, Ga., home and told his mom he hoped the Atlanta Falcons or Carolina Panthers called.

Or the Oakland Raiders. Riley, 28, would play for the Raiders.

“You said you didn’t want to go too far,” said his mom, Fonda. “California is far.”

“I would go that far to play with BJ,” her son said.

BJ is what family and friends call Irvin.

“The Raiders called Monday,” Fonda Riley said. “It was so amazing. Perry was so happy that he got to play with his best friend.”

Irvin said he didn’t like Riley until the seventh grade. And they saw each other often, living down the street from each other.

Finally, there was a spirited basketball game — “We used to go neighborhood versus neighborhood, serious stuff, like we were playing for money,” Irvin said — and the two weren’t roughing up each other, but on the same team.

“Ever since that day, we’ve been cool,” Irvin said. “We still compete over everything, but that’s just the kind of friendship we have. Real solid connection.

“He’s a dawg, just like me.”

Riley said Irvin and he would try to be on the same team in PE class, but “it was considered cheating. Being the fastest, strongest guys eventually brought us together and we became like brothers and the bond became unbreakable.”

(At this point, Irvin, a few lockers down, yells out, “Stop talking about all this personal stuff. It’s time to play football now.”

Irvin might want to cover his ears for this one, then.)

Riley was asked who won the early-years matchups?

“Football, basketball, kickball … ask him. … I did. I won most of those,” Riley said, laughing.

Irvin was the quarterback and Riley the running back, with both playing linebacker on defense, in middle school and into high school.

“They rode to school together, had sleepovers, were always in each other’s yard,” Perry Riley Sr. said. “Both kids loved to compete and loved to win, and they pushed each other. All the way to the NFL.”

They played together one season at Stephenson High, with Irvin at receiver as the Jaguars lost in the quarterfinals of the state tournament. The next year, Irvin dropped out of high school to earn money to help his mother and spent three weeks in jail on larceny challenges.

Irvin passed his GED the following year and got his football career back on track at Mt. San Antonio College in Southern California. His athleticism got him a shot at West Virginia, where he led the nation in sacks.

Riley went to LSU, and the friends then discussed about one day playing together again.

“We always talked about that,” Riley said. “Then, when he was going through the draft process, I was already at Washington and we got our hopes up, but no. Then, he called me as soon as Washington cut me. And here I am.”

Irvin is the starting outside linebacker. Riley started in place of the injured Malcolm Smith and is competing with him now for snaps. They will both have a lot of family and friends in the stands when the Raiders (4-2) play at Jacksonville on Sunday and then at Tampa Bay the following Sunday.

“It will be like a home game for us,” Riley said “My family’s first chance to see me as a Raider. I am fired up. … I am just here to help. We’re 1-1 since I got here, and we want to get that losing taste out of our mouths.”

Irvin actually cracks a smile when asked about his new teammate as a player.

“He doesn’t shy away from contact,” Irvin said. “His presence is definitely felt on Sunday.”

Briefly: Running back Latavius Murray (toe) was limited again in his second straight day of practice Thursday, but the coaches are hopeful he will play Sunday. ... Coordinator Ken Norton Jr. said that the league’s worst-ranked defense doesn’t need wholesale changes, “if you believe in your players, (if) you believe in your coaches.” Norton is tired of hearing about the team’s communication problems on the field. “It’s been fixed,” he said. “It just comes up at different times. It comes up at the worst times. There are a lot of plays that we have great communication on and people want to just bring out the ones you have bad communication on.”

Vic Tafur is a San Francisco Chronicle staff writer. Email: vtafur@sfchronicle.com Twitter: @VicTafur