The number 7 is a number of completion.
For the McDonald brothers, T.J. and Tevin, growing up, the number was "sacred."
As they prepped at Edison High School in Fresno, neither was able to wear it. Their dad, Tim, wore the number during his days at Edison, and the number was retired in his honor.
Tim starred as a safety for USC before playing in the NFL for 13 years, winning a Super Bowl with the San Francisco 49ers. T.J. is a junior at USC. Tevin is a redshirt freshman for UCLA.
They are now both allowed to wear the number 7 and play safety at rival schools. Dad's teachings stick with the boys on the field. He gave them three keys to playing the position:
"You have to play fast. You got to play physical and you got to have a playmaking mentality," said Tevin.
The younger McDonald has shown those skills in his first season on the field for the Bruins, while his brother is showing them off across town.
The two congratulate each other after games, and communicate in some form daily, --except this week.
"I congratulated him after they beat Oregon last week," said Tevin.
But that was the last time they talked.
In case you're unaware of the magnitude of the USC-UCLA rivalry, it's serious.
"That's my bro. I love him. I want him to have the best game he's ever had. He wants me to have the best game I've ever had but when it comes down to it, I want the team in blue to win," said Tevin.
It will be his first time being on the opposite side of his older brother, when UCLA (6-5, 5-3 Pac-12 South) goes to the Coliseum to take on USC (9-2, 6-2 Pac-12 South) on Saturday at 7pm on FOX
"We were always teammates, always on the same team, (the) majority of the time playing on the field at the same time," said Tevin. "I've never played on the opposite side of him (or) on the opposite bench of him so that'll be something new for me but I'm excited for it and my family is excited for it. I'm just ready to play."
Tevin's played a lot this season. A lot more than expected. He was third on the depth chart at free safety when the season began. After being thrust into the lineup after injuries, he now has eight starts under his belt.
Tevin made his first start of the season in replace of senior Tony Dye, who was out with a neck injury. Dye returned to the starting lineup last Saturday for Senior Day. Tevin was still in the starting lineup.
The pinnacle of his season, up to this point, came when he showed off his playmaking ability against Cal, picking off three passes to help the Bruins rebound from a disappointing loss at Arizona. His instincts are likely the strongest part of his game.
A part of that comes from his dad and his brother, who he's learned from. He's picked up from them not only how to play the position but also the physical nature that comes with it.
"It's not as much as me doing it because my that's how my dad played but being physical is a huge part of the game as a safety," said Tevin. "It just so happens that two really big role models of how to play physical are my dad and my brother."