San Antonio Spurs (2018–2022) On June 21, 2018, Walker was selected with the 18th overall pick by the
San Antonio Spurs in the
2018 NBA draft. Walker was later included in the 2018
NBA Summer League roster of the Spurs. On July 11, 2018, the Spurs announced that they signed Walker. On October 6, 2018, Walker was revealed to have a right medial meniscus tear. On November 25, 2018, the San Antonio Spurs assigned Walker the first time of the season to the
Austin Spurs. Walker made his NBA debut on January 3, 2019, in a 125–107 win against the
Toronto Raptors, scoring three points and grabbing one rebound in five minutes of play. On December 3, 2019, Walker scored a career-high 28 points, including 19 in the 4th quarter, in a 135–133 double overtime win over the
Houston Rockets with four rebounds, three steals and a block.
Los Angeles Lakers (2022–2023) in 2023 On July 6, 2022, Walker signed with the
Los Angeles Lakers on a one-year, $6.5M contract. He began the
2022–23 season playing in 32 games, all starts, before being sidelined beginning in late December with knee
tendinitis. At the time, he was averaging 14.7 points in 29.8 minutes per game and shooting 45.5% from the field and 38.9% on 3-pointers. After playing in a bit shy of 28 minutes through the first eight games of the
2023 playoffs, Walker returned to the rotation and scored 12 points in 25 minutes in a 127–97 win over
Golden State, giving the Lakers a 2–1 series lead in the conference semifinals.
Brooklyn Nets (2023–2024) On July 10, 2023, Walker signed a reported one-year contract with the
Brooklyn Nets. On June 29, 2024, Walker said after the season finale he was unsatisfied with the disrespect he received from the Brooklyn Nets' coaching staff and became a free agent after the season. On August 28, Walker signed a reported one-year contract with the
Boston Celtics, but was waived on October 19.
Žalgiris Kaunas (2024–2025) On October 30, 2024, Walker signed with
Žalgiris Kaunas of the
Lithuanian Basketball League (LKL) and the
EuroLeague. He helped Žalgiris win the
King Mindaugas Cup, the top domestic cup competition, on February 16, 2025. On February 19, he parted ways with the team in order to return to the NBA.
Philadelphia 76ers (2025) On February 21, 2025, Walker signed with his hometown team, the
Philadelphia 76ers. He made 20 appearances (seven starts) for Philadelphia, recording averages of 12.4 points, 3.2 rebounds, and 2.5 assists. After the NBA season, the 76ers declined to exercise their team option on Walker's contract, making him an unrestricted free agent.
Maccabi Tel Aviv (2025–present) On July 24, 2025, Walker signed a two-year contract with
Maccabi Tel Aviv of the
Israeli Basketball Premier League and the
EuroLeague. The contract is worth approximately $5 million gross. Deal includes NBA exit clauses for 2025, and 2026. ==Career statistics==