Harper played basketball for Pebblebrook High School in Mableton, Georgia. As a junior in 2014–15, Harper averaged 21 points and seven assists per game and led Pebblebrook to a school-best 27–6 record. Pebblebrook finished the season as Georgia Class 6A runners-up after losing to Joseph Wheeler High School, a team featuring top recruit Jaylen Brown, in the state title game. In July 2015, Harper was named co-most valuable player of the Nike Elite Youth Basketball League Peach Jam, scoring a 33 points and eight assists to help the Georgia Stars win the championship. In his senior season with Pebblebrook, he averaged 27 points, 10.1 assists, 5.7 rebounds and 3.7 steals, guiding his team to a 23–10 record and another Class 6A state championship appearance. Harper left high school as a two-time first-team All-State selection. He was a consensus four-star recruit in the 2016 class and committed to Auburn on March 19, 2015. His other NCAA Division I offers included Kansas State and Ole Miss.
College career
Harper averaged 11.4 points, 3.0 assists, and 1.2 steals per game, starting 30 games for Auburn in his freshman season. On January 7, 2017, he scored a season-high 24 points, including 16 of Auburn's final 19 points, in an 88–85 loss to Ole Miss. Harper was named SEC Freshman of the Week twice during the season. In 2017–18, through 34 games as a sophomore, he averaged 13.2 points, 5.4 assists, and 1.2 steals per game. On February 3, 2018, Harper posted a double-double of 14 points and 14 assists in a 93–81 win over Vanderbilt. He was one assist away from matching the school record for assists in a game, set by Eddie Johnson in 1976. One week later, Harper tied his scoring career-high, contributing 24 points and seven assists in a 78–61 victory over Georgia. He was a second-team All-SEC selection by the Associated Press and conference coaches. Harper made his junior season debut on November 6, 2018 by recording his second career double-double, with 20 points and 13 assists, in a 101–58 win over South Alabama. On December 15, 2018, he scored a career-best 31 points in a 75–71 overtime win over UAB. At the end of the regular season, Harper earned second-team All-SEC honors from the Associated Press and conference coaches.
Professional career
Phoenix Suns/Northern Arizona Suns (2019–2020)
After his junior season concluded, Harper declared his entry into the 2019 NBA draft, forgoing his senior year at Auburn. However, he went undrafted by the end of the event. Harper later played for the Phoenix Suns during the 2019 NBA Summer League in Las Vegas. Following his performance in the Summer League, he signed a two-way contract with Phoenix. On October 23, 2019, Harper made his NBA debut coming off the bench in a 124–95 victory over the Sacramento Kings. On December 20, Harper recorded 25 points and dished out a career-high 13 assists in a 94–99 loss to the Fort Wayne Mad Ants. On January 18, 2020, Harper scored 31 points to go with seven assists, four rebounds and two steals in the G League for the Northern Arizona Suns in a 120–109 loss to the Sioux Falls Skyforce. On March 14, Harper was waived by Phoenix.
