In eighth grade, Walker drew national attention for his slam dunks in highlight videos.[1] He often faced older competition, including high school seniors, in middle school with his Amateur Athletic Union (AAU) team Oakland Soldiers.[2] As a high school freshman, Walker played basketball for Moreau Catholic High School in Hayward, California, averaging 21.3 points, 6.5 rebounds and four assists per game.[3] After leading his team to a California Interscholastic Federation Division II runner-up finish, he was named MaxPreps National Freshman of the Year.[4] Entering his sophomore season, Walker transferred to Hillcrest Prep, a basketball program in Phoenix, Arizona, with his father, Khari, joining the coaching staff.[3][5] On October 25, 2019, during his senior year, he left Hillcrest Prep, intending to move to the college or professional level.[6] In December 2019, Walker graduated from high school but did not play high school basketball while weighing his options.[7]
Recruiting
On June 30, 2017, Walker committed to play college basketball for Arizona State over several other NCAA Division I offers. At the time, he was considered a five-star recruit and a top five player in the 2020 class by major recruiting services.[8] On October 21, 2018, Walker decommitted from Arizona State.[9] On April 20, 2020, as a four-star recruit, he announced that he would forego college basketball.[7]
Walker joined Chameleon BX to prepare for the 2021 NBA draft. For the 2021-22 season, he signed with the Capital City Go-Go of the NBA G League, joining the team after a successful tryout.[10]