The National Basketball Players Association is filing a grievance against the Sacramento Kings, challenging the legitimacy of the franchise’s voiding of free-agent forward Luc Mbah a Moute’s contract over an alleged failed medical physical, league sources told Yahoo Sports.

The NBPA is planning to file the grievance to the NBA early next week, league sources said.

Mbah a Moute has been meeting with NBPA executive director Michele Roberts in Johannesburg this week, where Mbah a Moute, a Cameroon native, has been medically cleared to play for Team Africa against Team World in the first NBA exhibition game in Africa.

Mbah a Moute signed a one-year, $1.5 million deal with Sacramento on July 14, and two days later had Kings officials inform him that concerns over his right shoulder had caused the franchise to void the deal, league sources told Yahoo Sports.

Mbah a Moute’s representatives at Wasserman Media Group and NBPA officials, armed with independent medical examinations that produced playing clearances, are disputing the legitimacy of the Kings’ process and the findings to declare a failed physical, league sources said.

Mbah a Moute played 67 games for the Philadelphia 76ers in the 2014-15 season – including 61 as a starter – without the shoulder causing him to miss time. Mbah a Moute averaged a career-best 9.9 points for the 76ers.

In seven NBA seasons with Milwaukee, Sacramento, Minnesota and Philadelphia, Mbah a Moute has averaged 6.8 points and 4.9 rebounds.