The Sixers have enough salary cap space to sign James to a $35.6 million annual max contract.
Fred VanVleet met with the Raptors on Sunday and both sides agreed to a two-year, $18 million deal.
The Celtics have full confidence in 20-year-old Williams, who will start off in the summer league next Friday.
Cousins received calls from the Lakers and Pelicans at the beginning of free agency and is expected to meet with both teams.
The Nuggets know it's a long shot, but after agreeing to terms with Nikola Jokic and Will Barton, Denver wants to meet with LeBron James.
The Clippers are still making the two-time All-Star a "high offseason priority" and the Lakers haven't been as aggressive with trade talks.
Rose began last season in Cleveland but was traded to Utah before eventually landing in Minnesota.
Chris Paul is staying in Houston, while Kevin Durant and Paul George have reportedly committed to the Warriors and Thunder respectively.
Green averaged 12.1 points and 3.2 rebounds in 41 appearances for the Rockets last season.