McClung went unselected in the 2021 NBA draft and spent time during the 2021–22 season with the Chicago Bulls and Los Angeles Lakers.

[3] He received his first significant exposure to basketball just before entering the seventh grade, when his mother Lenoir signed him up for a local youth league.

Scott Vermillion, who was McClung's coach at Gate City High School, recalled in 2018, "He ducked his head inside for a minute and basically never left.

[3] According to McClung, his shooting form improved after he broke his arm while snowboarding in eighth grade, and he honed the skill with Greg Ervin, the former head coach at Gate City High.

[5] McClung first started dunking as a sophomore playing varsity basketball at Gate City High School.

[8] After the season, he was averaging 29 points, 5.5 assists and three steals per game for the Blue Devils and was tabbed Southwest Virginia Boys' Basketball Player of the Year by the Bristol Herald Courier.

[9] On December 12, McClung made his senior debut by scoring 47 points, shooting 18-of-23, in a 96–43 win over Lee High School.

[10] On January 11, 2018, after opposing coach James Schooler reportedly told him "you're going to Georgetown to sit," McClung scored 44 points against Fern Creek High School of Louisville, Kentucky at the Arby's Classic tournament in Bristol, Tennessee.

The 47 points broke a VHSL all-classes scoring record for a championship game that had been held by former NBA player JJ Redick.

[12] McClung finished the season with 1,153 points and 2,801 for his career, also a VHSL all-classes record, and was again named Southwest Virginia Player of the Year by the Herald Courier.

[17] As a freshman, he averaged 13.1 points, 2.6 rebounds and two assists per game, leading Big East Conference freshmen in scoring.

McClung's debut with South Bay consisted of a game-high 24 points, nine assists and six rebounds in a 112–105 victory over the NBA G League Ignite on November 5, 2021.

[33] McClung debuted the next night, scoring 19 points and adding nine assists in a 112–108 loss to the Motor City Cruise.

[37][38] On June 29, Los Angeles declined his $1.62 million qualifying offer, making him an unrestricted free agent.

[50] On April 9, 2023, in Philadelphia's last game of the regular season, McClung recorded a near-triple-double with 20 points, nine rebounds and nine assists to help the 76ers defeat the Brooklyn Nets, 134–105.

During his birth, his umbilical cord was tightly wrapped around his neck; his father recalled, "He was blue as a Smurf."

His father served as trainer for much of his youth, and the family was able to afford placing him on a Richmond-based AAU travel team.

[2] His sister Anna, who completed her high school soccer career as the VHSL's all-time goal scoring leader,[3] played the sport at Florida State and Tennessee, and his uncle Seth competed with two Major League Baseball (MLB) teams.