Following one collegiate season at Duke, Barrett was selected by the Knicks with the third overall pick in the 2019 NBA Draft. He made his NBA debut on opening night Oct. 23 against the Spurs and posted 21 points (9-13 FG, 1-3 3Pt, 2-4 FT), five rebounds, two assists and two steals in 37 minutes. He appeared in 56 games during his rookie season, averaging 14.3 points, 5.0 rebounds, 2.6 assists and 1.0 steal in 30.4 minutes per contest. Barrett also shot 40.2 percent from the field, hit 1.1 threes per game at 32.0 percent and shot 61.4 percent from the charity stripe. Barrett set single-game career highs of 27 points, 15 rebounds, nine assists, six steals, five threes and two blocks. He had two double-doubles. On Oct. 25, Barrett's second game in the NBA, the guard swiped a career-high six steals, to go with 16 points, during a loss at Brooklyn. He twice scored a season-high 27 points, which included a 27-point, 5-rebound, 5-assists effort on Mar. 2 during a win at Houston. Arguably Barrett's best overall performance of the season occurred Mar. 11 during a win at Atlanta. In 39 minutes, he posted 26 points (9-14 FG, 2-5 3Pt, 6-6 FT), five rebounds, four assists, two steals and one block. That was Barrett's last performance in an eight-game double-digit scoring streak -- his longest of the season. During that stretch, he averaged 18.3 points on 13.8 shots, 4.6 rebounds, 3.5 assists and 1.3 steals across 31.3 minutes per game. Barrett had 13 games of 20-plus points, 31 games with at least five rebounds and eight games with at least five assists. He also swiped at least one steal in 33 games and blocked at least one shot in 16 games.