Richard Sherman's rivalry with Michael Crabtree pre-dates their time in one of the NFL's fiercest feuds. 

Before the outspoken cornerback and the wide receiver lined up against one another as members of the Seattle Seahawks and 49ers, respectively, Sherman used Crabtree as fuel during his time at Stanford. Sherman's older brother, Branton, learned when the two were children that he could motivate Richard by invoking the names of his opponents. 

Branton knew who to bring up when Richard started as a wide receiver at Stanford, the elder Sherman recalled in an interview with NBC Sports Bay Area's Matt Maiocco as part of a feature story that will run Thursday morning. 

“Bro, I don’t know who this guy Crabtree is over at Texas Tech, but he is doin’ numbers!” Branton remembered telling his brother.

“So what?" Richard replied, according to his brother. "He’s at Texas Tech. They throw every single play. He’s not all that good. He’s a’ight, he’s cool, but he’s not that good where those numbers match up to how good he is.”

Sherman moved to cornerback during his final two seasons at Stanford following a medical redshirt in 2008, while Crabtree won back-to-back Fred Biletnikoff Awards as the country's best receiver. The 49ers drafted Crabtree No. 10 overall in 2009, while Sherman fell to the fifth round in 2011. 

Crabtree and Sherman ultimately took the reins from then-49ers coach Jim Harbaugh and Seahawks coach Pete Carroll as the faces of the San Francisco-Seattle rivalry. During the 2013 NFC Championship Game, Sherman infamously called Crabtree a "sorry receiver" after the cornerback deflected then-49ers quarterback Colin Kaepernick's pass intended for Crabtree into the arms of Seahawks linebacker Malcolm Smith.  


[RELATED: How 49ers' Bosa has impressed Sherman on and off field]

Harbaugh and Carroll were rivals as coaches at Stanford and USC, respectively, but so were Sherman and Crabtree during their college playing days. 

Even if Crabtree didn't know it at the time.