The National Basketball Players Association has filed a grievance on behalf of Memphis Grizzlies forward Matt Barnes to get his two-game suspension without pay rescinded, league sources told Yahoo Sports.

The NBA suspended Barnes for a physical altercation with New York Knicks coach Derek Fisher in early October at the home of Barnes’ ex-wife in Southern California.

Barnes served a two-game suspension in late December, but NBPA executive director Michele Roberts is appealing to an arbitrator to spare Barnes the loss of $64,000 in salary, sources said.

The NBA did not announce a punishment for Fisher. The league’s investigation determined that Barnes was the instigator of the confrontation. Fisher alerted authorities, including police and the Knicks, in the immediate aftermath of the incident.

Barnes called Fisher a "snitch" in an Instagram post in January and wrote that Fisher should have taken "that ass whoopin like a man & kept it moving."

The Grizzlies play the Knicks in Memphis on Saturday.

As a player, Fisher was the NBPA’s president and played a part in the removal of Roberts’ predecessor, Billy Hunter.

Barnes initiated a physical altercation Oct. 3 in Redondo Beach, Calif., with Fisher, whom Barnes found at the home of his ex-wife, Gloria Govan, during NBA training camp. Fisher, once Barnes’ close friend and teammate on the Los Angeles Lakers, had developed a relationship with Barnes’ ex-wife and flew to California to spend a day with her on a Knicks off-day during camp.

The Grizzlies had finished a week of training camp in Santa Barbara when Barnes was in California.

Police were brought to the scene, but no charges were filed against Barnes. The NBA’s Collective Bargaining Agreement allows the league office to issue punishments for off-court issues whether or not formal criminal charges are filed, or a plea is ever rendered.

Fisher alerted the police about the altercation, and witnesses verified his account that Barnes had been an aggressor in provoking a physical confrontation. Fisher suffered minor bumps and bruises in the brief fracas, which included Barnes chasing Fisher from the backyard into the front rooms of the house.

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