In June 2018, reports surfaced claiming that Leonard had requested a trade from the Spurs and that he did so after months of tension between his camp and the Spurs stemming from a disagreement over his injury rehabilitation program.  A month later, on July 18, Leonard and teammate Danny Green were traded to the Toronto Raptors in exchange for DeMar DeRozan, Jakob Pöltl and a protected 2019 first-round draft pick.  In his debut for the Raptors in their season opener on October 17, Leonard had 24 points and 12 rebounds in a 116–104 win over the Cleveland Cavaliers.  Two days later, he had 31 points and 10 rebounds in a 113–101 win over the Boston Celtics.  On October 24, he scored 35 points in a 112–105 win over the Minnesota Timberwolves, helping the Raptors start the season 5–0.  On November 16, he recorded 31 points and a season-high 15 rebounds in a 123–116 overtime loss to the Celtics.  On November 25, Leonard received the first regular-season technical foul in his NBA career, while also recording 29 points and 12 rebounds in a 125–115 win over the Miami Heat.