The 7-foot-2 Kornet split the 2020-21 season between the Chicago Bulls and the Boston Celtics. His season started slowly in the Windy City, where Kornet appeared in only one of Chicago's first 21 games. But by early Feb. 6, the tall sharpshooter became a part of the Bulls' rotation, appearing in 11 of Chicago's next 16 games. Over that span Kornet averaged 2.2 points and 1.3 rebounds in 7.7 minutes per contest. During a Feb. 26 loss at Phoenix, Kornet posted 11 points, five boards, three blocks and three triples. Come March, Kornet fell out of the Bulls' rotation and was traded Mar. 25 with Moritz Wagner to Boston in a three-team deal. While Moritz struggled in Boston, Kornet excelled. Quickly nicknamed "The Green Kornet", the big center played in twelve of Boston's last 17 games, with two starts. As a Celtic, Kornet delivered 4.2 points, 2.6 rebounds and 1.5 blocks over 14.0 minutes per contest. On May 15, Kornet started, scored a season-high 12 points, and added six boards and four blocks in a win at Minnesota. The reserve center appeared in two of Boston's five playoff games versus the Nets. Kornet enters the off-season as an unrestricted free agent.

After two seasons with the Knicks, Kornet joined the Chicago Bulls for the pandemic-shortened 2019-20 season and appeared in 36 of 65 possible games for the Bulls. The lengthy center started 14 contests and for the season averaged 6.0 points, 2.3 rebounds and 0.9 three-pointers across 15.5 minutes per game. He shot a career-high 43.9 percent from the field and 28.7 percent from behind the arc. Arguably his best overall performance of the season occurred Jan. 31 at Brooklyn. Across 28 minutes, Kornet posted 19 points (7-11 FG, 2-4 3Pt, 3-4 FT), four rebounds, two assists (with no turnovers), one steal and one block. On Feb. 9, Kornet scored a new career-high 25 points (10-14 FG, 4-8 3Pt, 1-1 FT) to go with two rebounds and one block during a loss at Philadelphia. Kornet scored double-digit points in eight games, grabbed at least five rebounds in five games and dished out multiple assists in 11 games. He also recorded at least one block in 20 games. In the eight games that Kornet saw at least 24 minutes, he averaged 13.5 points, 4.5 rebounds, 1.4 assists and 1.3 blocks. An ankle injury forced Kornet to miss the Bulls' last nine games before the March sports stoppage.

Kornet's 2018-19 season with the Knicks was similar to his rookie year in New York. The 7-foot-1 center once again split his time between the G League's Westchester Knicks and the parent club in New York, but this time, he spent more time in the NBA. After playing in 20 games for the Knicks in 2017-18 (while appearing 36 times for Westchester), the Vanderbilt product played in 46 games with New York (and just 11 in the minors) in 2018-19. His per game stats with the parent club were similar to his rookie season, with the exception of his 18 starts. All told, Kornet played 17 minutes per game with averages of 7.0 points, 2.9 boards and 0.9 blocks. On Apr. 1, Kornet scored a career-high 24 points in a home win over the Bulls. Eight days later, Kornet hosted a block party in Chicago, swatting six shot attempts in another win over the Bulls. During that Apr. 9 contest, Kornet delivered his lone double-double of the season with 12 points and 13 rebounds. Kornet's 3-point shooting continued to blossom as well. The big center improved his behind-the-arc shooting to 36.3 percent, draining 1.5 treys per contest.

After a four-year career at Vanderbilt University, Luke Kornet spent most of his 2017-18 rookie campaign in the G League. He played 36 games for the Westchester Knicks, starting in 35 of those. He was later promoted to the NBA and suited up for 20 games with the New York Knicks, serving as an effective presence mostly off the bench. In the G League, Kornet averaged 16.1 points, 6.1 rebounds and 1.7 blocks on 48.9 percent shooting. He also shot 44 percent on 3-point attempts. Kornet averaged 6.2 points, 3.2 rebounds, and 1.3 assists in 16.3 minutes per game at the NBA level. He shot 39.2 percent from the field and 35.4 percent from beyond the arc. In his NBA debut, the 7-foot-2 big man recorded a double-double, scoring 11 points with 10 rebounds. Even more impressive, he also blocked four shots in that contest. Kornet scored in double digits on four other occasions. In the final game of the regular season, he scored a season-high 23 points on 9-of-14 shooting.