Sources - Brooklyn Nets' Ben Simmons files grievance to challenge nearly $20 million withheld by Philadelphia 76ers

Brooklyn Nets guard Ben Simmons has filed a grievance to challenge the nearly $20 million of salary withheld to him by the Philadelphia 76ers this season, setting up a potentially significant showdown, sources told ESPN on Saturday.

The grievance — which will now go to an arbitration process — could have larger league implications amid future issues of mental health matters and NBA contracts.

Philadelphia has repeatedly insisted that Simmons was in breach of his contract under the collective bargaining agreement between the NBA and National Basketball Players Association and had the right to recoup the money advanced him before the season. The NBA and NBPA have been at odds on this issue, and now arbitration could set a precedent on how future matters of mental health and contracts might be handled.

The filing was made with the team, NBA and NBPA late this week, sources said.

The 76ers have insisted that Simmons breached his player contract upon failing to show up for the starting of training camp and refusing to play during the preseason and regular season. Simmons arrived in Philadelphia near the end of the preseason, but cited mental health issues for the reason that his participation in team activities was so limited.

The 76ers and Simmons disagreed over the degrees of access that the team and its doctors were allotted to Simmons to diagnosis and affirm those mental health concerns.

In an attempt to resolve the matter without arbitration, Simmons' representatives had several conversations with the Sixers since the blockbuster trade to Brooklyn for James Harden on February 10, sources said. Those talks ended without a resolution, prompting the filing of the grievance, sources said.

Simmons and his agent Rich Paul of