Boston dealt all-star Kemba Walker and a first round draft pick to the Oklahoma City Thunder in deal that involves both players and draft picks changing hands, the Celtics announced on Friday. The Celtics are giving up guard Walker and a 2021 first round pick in exchange for centre Al Horford and prospect Moses Brown. This is the first significant move for Brad Stevens who replaced former president of basketball operations Danny Ainge in early June. The NBA clubs also exchanged second-round draft picks. Walker recently signed a four-year, $140.8 million contract with the Hornets. Walker, who is the Hornets' all-time leading scorer, struggled with knee injuries during the 2020-21 season. He was limited to 43 regular-season games and missed the final two games of the Celtics' loss to the Brooklyn Nets in the first round of the playoffs. The deal marks the return of Horford to the Celtics, where he played for three years before leaving in 2019. gph/dj