After re-joining the Memphis Grizzlies for the 2016 NBA Summer League, Harrison signed a multi-year deal with the team on July 12, 2016. On November 30, 2016, he scored a career-high 21 points in a 120–105 loss to the Toronto Raptors. Harrison made his debut in NBA playoffs on April 15, 2017, scoring 10 points in just under 20 minutes off the bench in a 111–82 loss to the San Antonio Spurs. On February 7, 2018, Harrison scored a career-high 23 points in a 92–88 loss to the Utah Jazz. A week later, he set a new career high with 28 points in a 121–114 loss to the Oklahoma City Thunder. Harrison missed nine games in March 2018 due to a right wrist injury. On November 1, 2018, Harrison was waived by the Grizzlies. On November 9, 2018, Harrison signed a two-way contract with the Cleveland Cavaliers. He was waived by the Cavaliers on December 2, 2018. On December 5, 2018, Harrison signed a two-way contract with the New Orleans Pelicans. He was waived by the Pelicans on January 8, 2019. On February 27, 2019, Harrison signed with Russian club Khimki for the rest of the 2018–19 season. On September 5, 2019, Harrison signed with the Golden State Warriors. On October 19, 2019, the Warriors released Harrison. Harrison ultimately landed on the roster of the Warriors’ G League affiliate, the Santa Cruz Warriors. Harrison averaged 15.5 points, 5.1 assists, 3.8 rebounds and 1.2 steals per game.