As a 16-year-old, Lewis moved to Spain to play for Fuenlabrada in the Liga ACB, where he went up from 2.3 minutes in three appearances during the 2021–22 season to 19 games in 2022–23 for almost 18 minutes per game and 4.8 points and 3.5 rebounds.[3] In May 2023, he produced the fourth-highest scoring game in ACB history by a player aged 18 or younger with 24 points against Obradoiro.[4]
Lewis joined the Mexico City Capitanes of the NBA G League for the 2023–24 season, where he played in 50 games and averaged 8.3 points and 5.8 rebounds in over 25 minutes per game.[3]
In July 2024, Lewis signed with the South East Melbourne Phoenix of the Australian National Basketball League (NBL) as part of the league's Next Stars program.[5][6] He became an important piece for the Phoenix over the course of the 2024–25 season, becoming one of the premier defenders on the team.[7] He scored a season-high 15 points in November 2024, and for the season averaged 6.8 points, 4.1 rebounds and 1.0 assists per game.[7]
In April 2025, Lewis declared for the 2025 NBA draft.[3][8] On 11 June 2025, he withdrew his name from the draft and subsequently returned to the South East Melbourne Phoenix for the 2025–26 NBL season.[9] On 6 November 2025, he scored a career-high 23 points in a 103–102 win over the Tasmania JackJumpers.[10][11] Later that month, he began suffering from pneumothorax, a condition that the affects lungs.[12] He missed a month of action due to pneumothorax and a hamstring injury.[13]