Mobley, along with his older brother, Isaiah, began playing basketball from an early age under the guidance of their father, Eric, a former basketball player. Evan was initially reluctant to play basketball but became more interested in the sport in eighth grade, when he stood 6'4. Mobley began playing high school basketball as a freshman at Rancho Christian School in Temecula, California. In his first three years, he was teammates with Isaiah, a five-star recruit in the 2019 class. As a junior, Mobley averaged 19.2 points, 10.4 rebounds and 4.7 blocks per game. He was named California Gatorade Player of the Year and The Press-Enterprise player of the year. In his senior season, Mobley averaged 20.5 points, 12.2 rebounds, 5.2 blocks and 4.6 assists per game, leading Rancho Christian to a 22–8 record. He repeated as California Gatorade Player of the Year, joining Jrue Holiday as the award's only two-time winners. Mobley was named Morgan Wootten National Player of the Year. He was also selected to play in the McDonald's All-American Game, Jordan Brand Classic and Nike Hoop Summit, but all three games were canceled due to the coronavirus pandemic.
Recruiting
Mobley is considered a five-star recruit and one of the three best players in the 2020 recruiting class. On August 5, 2019, he committed to play college basketball for USC over offers from UCLA and Washington, among other major NCAA Division I programs. Mobley became the highest-ranked player to join the program.
Mobley played for the United States at the 2018 FIBA Under-17 World Cup in Argentina. In seven games, he averaged 9.3 points, 5.6 rebounds and 2.6 assists per game, helping his team win the gold medal. Mobley joined the United States for the 2019 FIBA Under-19 World Cup in Heraklion, Greece, but he was limited to playing two games and a total of seven minutes in the tournament due to back spasms. His team won the gold medal despite his absence.
Personal life
Mobley's father, Eric Mobley, played college basketball for Cal Poly Pomona and Portland and played professionally in China, Indonesia, Mexico and Portugal. He later coached Amateur Athletic Union basketball for 11 years. In 2018, he was hired as assistant basketball coach for USC. Mobley's older brother Isaiah Mobley plays for USC. His mother, Nicol, is an elementary school teacher. Mobley grew up with three foster siblings, including a Chinese exchange student named Johnny.
