Warrick appeared in 68 games as a rookie, including two starts, and averaged 4.1 points and 2.1 assists in 10.6 minutes per game playing behind Pau Gasol. On January 31, 2006, Warrick was named to be one of the contestants in the NBA All-Star Slam Dunk Contest during the All-Star Weekend. He came in third place, behind New York Knicks guard Nate Robinson and Philadelphia 76ers forward Andre Iguodala. Warrick also played in three playoff games in his rookie season, as the Grizzlies were swept in four games by the Dallas Mavericks. On April 29, 2006, Warrick scored 11 points, including 7-of-8 free throws in a 94–89 overtime loss. Warrick started Game Four in place of Jake Tsakalidis. Warrick finished the playoff series with averages of 6.7 points and 2.3 rebounds per game.