In Washington's second season with the Hornets, the forward enjoyed an important role in the starting lineup and saw 30.5 minutes per game on the season while appearing in 64 games. The 22-year-old had an exceptional season, as he averaged 12.9 points, 6.5 rebounds, 2.5 assists, 1.2 blocks and 1.1 steals, which were all career highs. The former Kentucky star managed 10 double-doubles on the year to go along with 41 double-digit scoring performances. Washington had an impressive impact defensively for the Hornets, as he recorded four steals and three blocks on May 11 against the Nuggets. On Jan. 9, the forward logged a career-high six blocks in a win against the Hawks. Offensively, Washington had a large impact on the Hornets' scoring, as he recorded a career-high 42 points against the Kings on Feb. 28. The 6-foot-7 Hornet also matched a career-high six assists against the Mavericks on Jan. 13. Washington became a force on the glass, averaging 1.5 offensive rebounds per game, and he grabbed a career-high 13 rebounds against the Spurs on March 22. The forward's free-throw percentage took a big leap from his rookie season, as he made 74.5 percent from the charity stripe. In his play-in debut, Washington almost achieved a double-double, as he managed eight points and seven rebounds to go along with two blocks against the Pacers on May 18.

Following two collegiate seasons at Kentucky, Washington was selected with the 12th overall pick by the Charlotte Hornets in the 2019 NBA Draft. He made his NBA debut Oct. 23 against the Bulls. In that game, he played 38 minutes and posted 27 points (9-17 FG, 7-11 3Pt, 2-2 FT), four rebounds, one assist, a career-high seven three pointers, one steal and one block. The 27 points remained his career-high through his rookie season. Two nights later, Washington registered his first career double-double with 10 points and 10 boards during a home loss to Minnesota. Washington had four double-doubles on the season. On Jan. 8, the 6-foot-7 forward grabbed career-high 12 rebounds during a close home loss to the Raptors. Washington's other single-game career highs were established at six assists, four steals and four blocks. Overall, he averaged 12.2 points, 5.4 rebounds, 2.1 assists, 0.9 steals and 0.8 blocks in 30.3 minutes per contest. Washington shot 45.5 percent from the field and 37.4 percent from behind the arc with 1.5 made three-pointers per game. He had seven games with 20-plus points, 38 games with at least five rebounds and 27 games with at least three assists. He had 13 games with multiple steals and 10 games with multiple blocks. In September, the Kentucky product was named to the All-Rookie Second Team.