Antonio Brown absent from the practice of Raiders, always upset by the change of helmet | Bleacher's report

Oakland Raiders Browns receiver Antonio Brown has yet to show up to train and remains unhappy with his NFL helmet conflict.

Chief Executive Mike Mayock explained the situation on Sunday:

"At this point, we have almost exhausted all the escape routes," said Mayock. "So, from our point of view, it's time for him to be complete or total."

Brown filed a grievance with the NFL to use his old helmet, but he denied by an arbitrator.

Brown initially seemed to have overcome the problem after his first statement on Twitter, but he showed his anger at Saturday's situation:

The recipient also dealt with frostbite on his feet, which made him stay off the field.

While Brown was with the team at the pre-season match of the second week against the Arizona Cardinals, even race routes during warm-ups, he stays away from the team during the practice.

The Raiders remained patient with the All-Pro player, but Mayock has clearly reached a breaking point before the important match of the pre-season of the 3rd week against the Green Bay Packers.

Oakland has acquired Brown this season in a deal with the Pittsburgh Steelers, hoping to add production to a Pro Bowler seven times. However, off-field concerns have been the biggest story of this pre-season.