Source: https://www.espn.com/nba/story/_/id/38380166/sources-nba-likely-pass-tougher-rules-resting-stars
Teams must manage their roster to ensure that no more than one star player is unavailable for the same game.
Teams must insure that star players are available for national television and in-season tournament games.
Teams must maintain a balance between the number of one-game absences for a star player in home games and road games -- with a preference for those absences to happen in home games.
Teams must refrain from any long-term shutdown -- or near shutdown -- when a star player stops participating in games or plays in a materially reduced role in circumstances affecting the integrity of the game.
Teams must insure that healthy players resting for a game are present and visible to fans.
The NBA will provide several scenarios for excused absences on missed games -- including those involving regular-season back-to-back scenarios, sources said. For example, the NBA will allow pre-approved designated back-to-back allowances for players who are 35 years old on opening night or have career workloads of 34,000 regular-season minutes or 1,000 regular season/playoff games combined, sources said.