Antonio Brown reportedly is attempting to recoup some of the money he lost when the Oakland Raiders released him on Sept. 7.

ESPN's Jeremy Fowler reported Brown and the NFL Players Association are exploring ways to get the controversial wide receiver at least some portion of the $30 million in guaranteed money from his Raiders contract.

According to Fowler's source, there are multiple grievance options being considered by Brown that include three fines levied by the Raiders, "his unpaid Week 1 salary, his base salaries of $14.625 million and $14.5 million for 2019 and 2020, and a $1 million signing bonus as part of his three-year, $54-million deal signed in March."

ESPN's Adam Schefter reported Brown's $215,073.53 in fines for conduct detrimental to the team voided the $29.125 million guaranteed money on his contract, and he received a letter from the Raiders informing him he wasn't entitled to termination pay. 

Per ESPN's Chris Mortensen, Brown filed a grievance against the New England Patriots on Sept. 22 for the $10 million in guaranteed money in his contract. 

Five NFL sources told Yahoo Sports' Charles Robinson the New England Patriots will almost certainly have to pay him the $9 million signing bonus that was part of his one-year deal before he was cut by them on Sept. 20. 

Brown is currently under investigation by the NFL in the wake of his former trainer filing a federal lawsuit accusing him of sexual assault and rape. A second woman accused Brown of sexual misconduct and intimidation. 

Fowler noted the Patriots were scheduled to give Brown $5 million on Sept. 23, but decided not to because they intend to argue he breached his contract. 

Brown is currently a free agent and eligible to sign with any team, but he is also subject to suspension under the NFL's personal-conduct policy.