Martin saw plenty of overall improvement in his game throughout his second season with the Hornets, as he improved his rebounding efficiency and recorded fewer turnovers. The guard averaged 5.0 points, 2.7 rebounds, 1.3 assists and 0.7 steals in his 53 games. The 25-year-old started in two games and had two of his best games of the season in those games. In his first start of the year on April 13, Martin logged his first career double-double with 17 points, 10 rebounds and five assists against the Lakers. Martin set a career-high 10 rebounds and matched a career-high five assists in that game versus the Lakers. His second start of the season came against the Pistons on May 4 and it proved to be a good one defensively for Matin as he put up 17 points, five rebounds, two steals and a block. The former Nevada standout performed well defensively all year, finishing with 26 games with at least one steal and 10 games with at least one block. In Martin's play-in debut, the 6-foot-5 guard posted an impressive eight points, one assist and a steal in only six minutes of play against the Pacers on May 18. On the year, Martin averaged only 15.4 minutes per game, however, he finished the year with seven double-digit scoring performances. Overall, the second-year Martin improved in plenty of different areas, but his offensive rebounding ability became critical as he had 21 games with at least one offensive board.

After going unselected in the 2019 NBA Draft, Martin signed a contract with the Hornets. He made his NBA debut Oct. 25 against the Timberwolves. In that contest, he played 18 minutes and recorded four points (2-8 FG, 0-2 3Pt, 0-1 FT), three assists, two rebounds, two blocks and one steal. He had his first double-digit scoring game (and also a career high at the time) Feb. 25 against the Pacers. In 26 minutes, Martin posted 11 points (4-10 FG, 3-4 3Pt), three rebounds, two assists and one block. Martin's first career 20-point game, which remained his career high, came on Mar. 9 against the Hawks. In 37 minutes, he posted 23 points (8-10 FG, 5-6 3Pt, 2-2 FT), four assists, three steals and two blocks. Martin's other career highs were set at seven rebounds, five made threes, four assists, four steals and two blocks. Overall, Martin appeared in 18 games, averaging 6.2 points, 2.1 rebounds, 1.3 assists, 0.7 steals and 0.4 blocks. He shot 44.0 percent from the field, 54.1 percent from three and 81.0 percent from the free-throw line.