ALAMEDA, Calif. — Star receiver Antonio Brown practiced in a certified helmet with the Oakland Raiders on Tuesday, two days after being given an ultimatum by general manager Mike Mayock to be “all in or all out.”

“He’s all in, ready to go,” coach Jon Gruden said. “That’s my understanding. Really happy to have him out here. He’s a great player.”

Brown didn’t attend practice Sunday as he worked to find a helmet he was comfortable using and that met safety standards set by the NFL and NFLPA. He lost a grievance last week in which he sought to be allowed to use the Schutt Air Advantage helmet he has worn throughout his career.