Texas Legends (2019–2020) Roby was drafted 45th by the
Detroit Pistons and traded to the
Dallas Mavericks. On August 7, 2019, Roby officially signed with the Mavericks. The Mavericks assigned him to the
Texas Legends for the start of the
NBA G League season. He suffered from
plantar fasciitis, which caused him to miss several games for the Legends.
Oklahoma City Thunder (2020–2022) On January 24, 2020, Roby was traded to the
Oklahoma City Thunder by the Mavericks in exchange for
Justin Patton and cash considerations. He did not appear in a game during his time with the Mavericks. He made his NBA debut with a brief appearance for the Thunder in January 2020. He was then assigned shortly thereafter to the
Oklahoma City Blue, returning to the main Thunder roster for only a single day before being sent back to the Blue. On December 29, 2020, Roby scored a season-high 19 points, alongside seven rebounds and two blocks, in a 107–118 loss to the
Orlando Magic. On March 28, 2022, Roby scored a career-high 30 points, alongside eight rebounds, four assists and two steals, in a 134–131 win over the
Portland Trail Blazers. On July 3, Roby was waived by the Thunder.
San Antonio Spurs (2022–2023) On July 5, 2022, Roby was claimed off waivers by the
San Antonio Spurs. He made his Spurs debut on October 19, recording five points and two rebounds in a 102–129 loss to the
Charlotte Hornets. On March 3, 2023, Roby was waived by the Spurs.
Westchester Knicks (2023–2024) On April 9, 2023, Roby signed with the
New York Knicks, but was waived on October 18 without playing for the Knicks. Three days later, he re-signed with New York, but was again waived that day. On November 9, Roby was named to the opening night roster for the
Westchester Knicks.
ratiopharm Ulm (2024–2025) On July 19, 2024, Roby signed with
ratiopharm Ulm of the
Basketball Bundesliga. ==Career statistics==