Oakland Raiders to suspend wide receiver Antonio Brown, ESPN reports

OAKLAND, Calif. (KGO) -- Star receiver Antonio Brown's future with the Oakland Raiders is uncertain Thursday afternoon.

Our sister network ESPN is reporting that Brown is facing a suspension over a confrontation Wednesday with General manager Mike Mayock.

Reports say the incident involved Brown's posting of a letter from Mayock on social media, informing the receiver that he had been fined.

RELATED: AB reacts to fines from Raiders, has new helmet

Brown was not at practice on Thursday.

Neither Mayock nor Coach Jon Gruden is saying why.

RELATED: Oakland Mayor Libby Schaaf's message to Antonio Brown

If suspended, the Raiders could void $29 million in guarantees in Brown's contract he signed earlier this year.

It's been a tumultuous pre-season for the 31-year old, from a case of frostbitten feet, to a confrontation with the NFL over his helmet.

ESPN has contributed to this report.