Lance Thomas played 46 games in 2018-19 in his fifth season with the Knicks. He started 17 of those contests and came off the bench for the remaining 29. Though his 17.0 minutes per game marked a slight decrease from the previous season, he increased both his scoring and rebounding rates, averaging 4.5 points and 2.5 rebounds per game. Thomas underwent knee surgery in early November and missed over a month of action, but he maintained his health through the latter part of the campaign, playing in 20 straight contests until a personal matter kept him out of the final three games of the season. Thomas posted his finest stat line of the campaign in a victory over the Spurs on Feb. 24, logging 30 minutes and scoring a season-high 16 points on 7-of-13 shooting from the field while pulling down seven rebounds. He also connected on a pair of three-pointers in the contest, one of five occasions last season in which he drilled multiple treys in a game. Thomas' free-throw shooting fell below 80.0 percent for the first time in four years, but he still hit a respectable 75.0 percent from the line. He also made valuable contributions that did not show up in the box score. Last season's longest-tenured Knick lived up to his career calling card by serving as a source of energy and tough defense for New York.

Thomas was named a team captain ahead of his fourth season in New York. The seventh year pro would go on to play in a career-high 73 games, making 31 starts and averaging 4.1 points and 2.4 rebounds in 18.5 minutes per game. He matched a career-best by making three three-point shots on three different occasions in the season. Thomas scored a season-high 14 points and grabbed seven rebounds against Cleveland on April 9. Thomas would make a career-high 50 three-point shots on the year. He recorded a season-high three assists against Memphis on January 17. The Duke product scored 13 points against San Antonio on January 2. He recorded a season-high +26 against Memphis on December 6 while scoring eight points and pulling down four rebounds. He went 6-for-6 on free throws against Orlando on February 22. He grabbed four offensive rebounds against Charlotte on December 18.