Yet, unlike some athletes, who might be satisfied with a fashion show appearance or two, Mr. Westbrook has greater ambitions. Over a recent lunch, dressed in a fitted black tee and dark bluejeans that he had cut into capris (a silhouette he’s liking right now, he explained), he kept circling back to his need to stand out, to “shift to a different lane and find my own way.” Perhaps unsurprisingly, one day, he would like to have a line. He also consistently works with a tailor, Johanna Alba who, for better or worse, sews custom designs for him.

“She knows what I like,” Mr. Westbrook said simply. His greatest fashion influence, however, has been his mother, he said.

Mr. Westbrook was born in Los Angeles to Russell Westbrook Sr. and Shannon Westbrook, the oldest of two (his brother, Raynard, 22, is a running back for the University of Central Oklahoma). His family moved around the city a lot when he was younger, he said, before settling in an apartment in Hawthorne, where he attended Leuzinger High School. It wasn’t posh, but it also wasn’t what some may assume about his inner-city childhood, he said. “Hawthorne, it changed,” he said. “It was quiet when we moved there, but by the time I was in 9th or 10th grade it was a little rugged, a little rough.”

Besides, his home life was happy. His mother, who worked in a public school cafeteria in Los Angeles, “liked her job,” Mr. Westbrook said. “And I always got free food,” he said, grinning. His father was on a production line, working in a factory that manufactured tires for airplanes. Since he started playing in the N.B.A., both have since “retired,” he said.

As a freshman, Mr. Westbrook wasn’t a big kid. He played football, baseball and basketball, standing at just 5-foot-6. He eventually focused on basketball on account of his size 12 feet. “I thought I’d grow into it,” he said. (Today, his height is a plus for designers and fashion editors. “He can wear the designer samples,” Mr. Bedard said.) It was also around then that “I started becoming very picky,” he said. Growing up, his mother used to buy his clothes for him and she was always “following and knowing what the trends were.” He started to choose his own colors and pieces, like “I used to wear Girbaud jeans and Rocawear,” he said. “Definitely my clothes were big.”