Brown requested his release Saturday morning in a post on Instagram after the Raiders voided the guarantees in his contact by fining him over $215,000 for conduct detrimental to the team following an altercation with general manager Mike Mayock, per ESPN's Adam Schefter.
Brown explained his rationale to NFL Network's Ian Rapoport: "Told me do not come in Thursday. Bad my name. Then come work, give two papers after the press conference. No guaranteed no way."
Brown is now a free agent and free to sign with any team.
"Now that Antonio is a free agent, we are focused on the future and I will immediately work on signing him to a new team. Antonio is looking forward to a new beginning," agent Drew Rosenhaus told Schefter.
The first few months of Brown's Raiders tenure went well after Oakland traded for the ex-Pittsburgh Steelers superstar and signed him to a three-year, $50.1 million deal ($30.1 million guaranteed).
However, everything started going south at the start of training camp when he reported to Napa, California, with frostbitten feet from failing to wear proper footwear in a cryotherapy chamber. He was placed on the non-football injury list, but all seemed well after he returned to practice just a few days later.
But the feet were still bothering him, as was the NFL's edict that Brown replace his banned Schutt Air Advantage helmet. He left camp midway through practice July 30 and filed a grievance with the league to keep his headgear.
Brown returned to camp two weeks later but again left the team Aug. 18 after losing his grievance.
In response, the team showed its first sign of displeasure, with general manager Mike Mayock telling reporters AB had to be "all-in or all-out":
The answer initially appeared to be all-in, as Brown returned to the team a second time the following day and even traveled with the Raiders to a preseason game against the Green Bay Packers in Winnipeg, Manitoba.
He lost a second grievance against the NFL on Aug. 25, though no other drama ensued through Labor Day weekend.
Any peace between Brown and the Raiders evaporated, however, when Mayock sent Brown a letter detailing fines for an unexcused camp absence and a missed walkthrough ahead of the Packers game.
Brown, in turn, posted the letter on Instagram along with an all-caps message: "WHEN YOUR OWN TEAM WANT TO HATE BUT THERE'S NO STOPPING ME NOW DEVIL IS A LIE. EVERYONE GOT TO PAY THIS YEAR SO WE CLEAR."
Brown had an eventful Wednesday practice that included catching a pass from quarterback Derek Carr and then firing the football at a fence, arguing with a strength and conditioning coach and reportedly getting into a confrontation with Mayock.
Rapoport provided details:
On Thursday, Schefter reported the team was planning to suspend Brown. Later, Mayock held a 13-second press conference to address the situation:
The suspension never occurred, as Brown returned to the team Friday and apologized publicly and privately. Head coach Jon Gruden told reporters Brown would play against the Denver Broncos in their Week 1 opener Monday.
The drama continued Friday evening, however, when Brown posted a video showcasing a phone conversation with Gruden as well as the wideout's apparent displeasure with how the media has portrayed him.
One of the game's top stars is now a free agent, and Oakland is without the biggest piece of its 2019 puzzle.
The Silver and Black will turn to Tyrell Williams to fill the void at the No. 1 wideout spot. The ex-Los Angeles Charger caught 41 passes for 653 yards and five touchdowns last season. He's capable of putting up bigger numbers, however, as he snagged 69 receptions for 1,059 yards and seven touchdowns in 2016.
Williams also had to fill the void of a No. 1 receiver that year after Keenan Allen suffered a torn ACL in Week 1.
Rookie slot receiver Hunter Renfrow figures to get more looks, and the same goes for tight end Darren Waller. J.J. Nelson could round out the offense in three-wideout sets.
Brown, a four-time All-Pro, has 11,207 receiving yards and 74 touchdowns in just nine seasons. He's led the league in receptions and receiving yards twice apiece.