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_).