ESPN and The Athletic reported Sunday that Irving, 27, will sign a four-year, $141 million contract with the Nets. The former No. 1 overall pick averaged 23.8 points, five rebounds and 6.9 assists in 67 games with the Celtics last season.
NBA free agents were able to reach agreements with teams beginning 6 p.m. Eastern time Sunday. The contracts cannot officially be signed until Saturday.
Irving replaces D'Angelo Russell, who the Nets acquired for longtime center Brook Lopez in June 2017. The Celtics are expected to replace Irving with Charlotte Hornets point guard Kemba Walker, according to ESPN and The Athletic.
Irving was the No. 1 overall pick of the Cleveland Cavaliers in 2011 and won a title with the franchise in 2016. He was traded to the Boston Celtics in July 2017.
Irving is a six-time All-Star who has averaged 22.2 points and 5.7 assists in 508 career games.