Jefferson attended Central High School in East Chicago, Indiana. As a senior, he averaged 26.1 points and 8.1 rebounds per game and was named The Times of Northwest Indiana Player of the Year.[1] Jefferson led his team to a Class 4A sectional title and was named an Indiana All-Star.[2] He committed to playing college basketball for New Mexico, his father's alma mater.[3]
College career
Jefferson averaged 5.3 points and 2.3 rebounds as a freshman at New Mexico. For his sophomore season, he transferred to Creighton and sat out for one year due to transfer rules.[4] As a sophomore, Jefferson averaged 6.2 points and four rebounds per game before his season was cut short due to a high ankle sprain injury.[5] In his junior season, he averaged 9.4 points and 5.5 rebounds per game. Jefferson declared for the 2020 NBA draft before withdrawing and returning to college.[6] On December 17, 2020, he flirted with a triple-double, recording 10 points, 10 rebounds and eight assists in a 94–76 win over St. John's.[7] As a senior, Jefferson earned Second Team All-Big East honors.[8] He averaged 11.9 points and 5.4 rebounds per game. Jefferson declared for the 2021 NBA draft, forgoing an additional season of eligibility the NCAA granted due to the COVID-19 pandemic.[9]