Coffey was born in Hopkins, Minnesota to Richard and Sheba Coffey. His father played college basketball for the University of Minnesota from 1986-90 and went on to play for the Timberwolves. Coffey has two older sisters -- Sydney and Nia -- who played college basketball. Nia currently plays for the WNBA's San Antonio Stars. Coffey attended Hopkins High School in Minnetonka, Minnesota. He was named Associated Press State Player of the Year and Minnesota Mr. Basketball as a senior. That season, he averaged 19.9 points per game. He played in the 2016 Jordan Brand Classic, scoring seven points and collecting two rebounds along with two assists. Learn more about Coffey by following him on Twitter and Instagram (@coffeyshop_). Coffey attended the University of Minnesota for three seasons under coach Richard Pitino. As a freshman, he ranked second on the team in both points (12.2) and assists (3.1) per game. He was named to the Big Ten All-Freshman Team. The Golden Gophers qualified for the NCAA Tournament as a five-seed but bowed out to Middle Tennessee State in the first round. Coffey suffered a shoulder injury during his sophomore campaign and ended up playing only 18 games. Nonetheless, his per-game averages increased to 14.0 points, 4.1 rebounds and 3.3 assists. Coffey returned forcefully for his junior season, establishing a career-best scoring average of 16.6 points per game. Following the campaign, he was named Third-Team All-Big Ten. Minnesota again qualified for the NCAA Tournament and upset Louisville in the first round. In the victory, Coffey scored 18 points and grabbed six rebounds. In the second round, the Golden Gophers were defeated by Michigan State. Following his junior season, Coffey declared for the 2019 NBA Draft. He went undrafted in the draft but later signed a two-way contract with the Los Angeles Clippers.