The team will be coached by Gregg Popovich, one of James' favorite coaches. "I love everything about Pop, obviously, but this is not a good summer for me," James said.
Instead, James will train and film "Space Jam 2," which will be released in July 2021.
According to The Athletic, the movie's production schedule was set based on the knowledge that James would not play this summer.
James will miss the NBA postseason this year for the first time since 2005. The Lakers missed the playoffs again this season, and James' own season ended last week following a groin injury. He won't play another game until October.
But James, a two-time Olympic gold medalist, has not ruled out playing for Team USA in the 2020 Summer Olympics in Japan.
"Yeah, that's a possibility," James told The Athletic. "It depends on how I feel. I love the Olympics."