Wide receiver Antonio Brown will be at the Oakland Raiders' facility in Napa, California, on Tuesday, a source told ESPN's Adam Schefter.

And Brown, who has not been with the Raiders since being limited in a practice and leaving early on July 30, is looking for help from fans -- with a little incentive, of course -- to obtain a "new" old helmet.

He posted on social media Monday that he was looking forward to rejoining his teammates on the field after he lost a grievance against the NFL over wearing his old helmet.

On Friday, Brown had a two-hour conference call with an independent arbitrator to argue why he should be allowed to wear his older helmet -- a 10-year-old Schutt Air Advantage model -- which he is thought to have been using his entire career. Brown's specific helmet is over 10 years old and the model is no longer made by the company, so it is not currently certified by the National Operating Committee on Standards for Athletic Equipment.

The wide receiver took to social media Tuesday to find a version of his preferred-style helmet that is less than 10 years old. It is not clear whether, if Brown could even find one and get it certified by NOCSAE, the NFL would sign off on it, because the technology is outdated.

"I'm looking for a Schutt Air Advantage Adult Large Helmet that was manufactured in 2010 or after. In exchange I will trade a signed practice worn helmet."

— AB () August 13, 2019

Brown has tried out the new certified helmet and believes it protrudes and interferes with his vision as he tries to catch the football. He also argued that his helmet made him feel safe.

He had reportedly threatened to retire if he was not allowed to wear his helmet. He was acquired from the Pittsburgh Steelers in March and promptly given a three-year, $50.125 million contract.

Brown has also been dealing with frostbitten feet suffered in a cryotherapy mishap in France last month.

ESPN's Paul Gutierrez contributed to this report.