Oakland Raiders wide receiver Antonio Brown posted on social media a letter he received from the team that detailed about $54,000 in fines for missing time during training camp.

Brown's response, in part: "Everyone got to pay this year."

The notice, posted on Instagram on Wednesday, was from Raiders general manager Mike Mayock, who informed Brown that he was being fined $13,950 for missing a walk-through on Aug. 22, an unexcused absence. Brown was with the team in Winnipeg for a preseason game that day.

The letter also mentions that the team previously had fined Brown $40,000 for missing camp on Aug. 18 -- the day the GM issued his ultimatum to Brown, saying, "It's time for him to be all-in or all-out, OK?"

Mayock also advised Brown that should he continue to miss mandatory team activities, including practices and games, the Raiders reserved the right to impose additional fines and discipline.

Brown wrote in an Instagram story:

Antonio Brown posts his displeasure with fines from #Raiders pic.twitter.com/0OMhdwFu7K

— Vic Tafur () September 4, 2019

Brown was acquired in a March trade for a third- and a fifth-round draft pick. After being a mainstay during the team's offseason program, Brown began camp on the non-football injury list because of frostbite on the soles of his feet after a cryotherapy mishap in France in early July.

He left camp for two weeks seeking therapy for the feet, which included laser treatments.

Brown was also upset with the league's not allowing him to wear his Schutt Air Advantage helmet, the only helmet he has worn in his NFL career, because it is older than 10 years, thus no longer certified. He lost two appeals to use the old helmet, and is now working on getting one he likes approved by the league.