The Houston Rockets remain hopeful Clint Capela, 24, will agree a new deal.
Thomas signed with the Nuggets this month but had reached out to Celtics general manager Danny Ainge before his contract was finalized.
The Hawks will waive the veteran after officially acquiring him from the Thunder, leaving him to sign with Houston.
Smith and James seemingly had a pretty close relationship during their time together in Cleveland, fourth-quarter meltdowns aside.
Harris averaged 19.3 points and six rebounds in 32 games with Los Angeles last season.
Fultz averaged 7.1 points per game and attempted a single 3-pointer in just 14 regular season appearances as a rookie.
Anthony reportedly was traded Thursday from the Thunder to the Hawks, but he is expected to be waived and become a free agent.
Babbitt is a career 40.2 percent 3-point shooter while Booker averaged 6.3 points in 68 games last season.
Len averaged 8.5 points and 7.5 rebounds in 69 games for the Suns last season.
Los Angeles and Harrell agreed to a two-year, $12 million contract Saturday, according to a report from ESPN.