The NBA is investigating the Philadelphia 76ers for a potential breach of the league's new Player Participation Policy, according to league insider Adrian Wojnarowski of ESPN.

Before their scheduled season-opener away game against the Milwaukee Bucks on Thursday, October 26, the team sent star James Harden back home instead of having him join the team on the plane.

The Sixers' game against the Bucks will be on national television, and the league's new rules require star players to be available in such games unless there exists an approved reason for their absence.

Despite the 2018 NBA Most Valuable Player's desire to accompany the team on their opening road trip to Milwaukee and Toronto, the Sixers were hesitant to include him due to concerns about his physical readiness.

Harden coming off a prolonged absence

The team gave the 33-year-old a 10-day excused absence to deal with a personal matter, with rumors suggesting that the ten-time NBA All-Star was caring for his ill mother.

Harden has not participated in any five-on-five scrimmages with the Sixers, which added to the uncertainty surrounding his preparedness for the season opener.

Wojnarowski added that his only preseason scrimmage with the team occurred on October 7 in Boston.

The 2012 NBA Sixth Man of the Year had been away from the team for an extended period, and the team felt he wasn't adequately prepared to participate in the upcoming games.