Oakland Raiders wide receiver Antonio Brown's continuing helmet saga struck what could be its endpoint on Monday after his grievance case against the NFL fell through.

To recap, Brown, the 31-year-old wideout acquired by the Raiders in the offseason in a trade with the Pittsburgh Steelers, has been away from full practice at Oakland's Napa, California, training camp. At first the belief was his foot injury—rumored to be caused by improper footwear while receiving cryotherapy—was holding up Brown's preseason debut and participation in practice for the Raiders. Later, it was reported that Brown took issue with the league's updated safety regulations with its “new” helmet.

Brown had preferred to keep wearing the old style of helmet and reportedly threatened to retire if he couldn't keep his favorable headwear.

Now, per NBC Sports' ProFootballTalk, there appears to be a loophole in the safety policy that could provide Brown a helmet solution to his liking.

Brown can’t use his preferred helmet — a Schutt AiR Advantage — in 2019, because that specific helmet is more than 10 years old. However, because the NFL has not affirmatively banned from use the Schutt AiR Advantage, Brown apparently could use one that is less than 10 years old, if he can find one.

In response to that specific inquiry, the NFL forwarded to PFT a graphic containing the 11 helmet models that became prohibited as of 2019; the Schutt AiR Advantage is not on the list.

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[If] Brown can find a Schutt AiR Advantage in his size that was made in or after 2019, he could get that specific helmet certified and use it this year. Because the Schutt AiR Advantage was discontinued in 2011, he has only a narrow window before it will be impossible to recertifiy any versions of the Schutt AiR Advantage.