Andrew Luck injury update: Colts QB (lower leg) won’t practice this week Antonio Brown heads into the team’s performance center as practice starts and helmets come on. pic.twitter.com/6hUg4jTKom— Scott Bair (@BairNBCS) August 20, 2019Brown reportedly returned to the Raiders on Monday as the team broke training camp in Napa, Calif., but filed another grievance against the NFL over the issue.Per NFL.com:“(Brown is) arguing that he should be afforded the same rights provided to other NFL players to have a 1-year grace period to phase out his helmet in the 2019 season. He claims the NFL is arbitrarily applying rules.”It’s been a messy couple weeks for Brown. First, the helmet he had worn with the Steelers was removed from the NFL’s approved list and he lost an arbitration appeal to use the old model earlier this month. Then, Brown and the NFL reached a compromise which would have allowed him to use the helmet model he likes if he could find one made within the past 10 years. “He’s all in and ready to go,” Gruden told reporters. “That’s my understanding. Really happy to have him out here. He’s a great player.”After partaking in the walk-through before the workout, Brown was seen exiting the field and heading to the weight room as practice started and helmets came on, though he later returned for the end of the team’s stretch. Related News Julio Jones’ agent headed to Atlanta to talk new Falcons deal, report says Jimmy Garoppolo ‘obviously a little frustrated’ with lackluster preseason debut Could there be an end in sight for the Antonio Brown helmetgate?According to Raiders coach Jon Gruden, the wide receiver is “all-in” and “ready to go” after participating in Tuesday’s practice at the team’s facility with a certified helmet. However, the league reversed that decision Sunday after the helmet he chose went through additional testing and failed.Should Brown’s latest helmet actually clear all the hurdles with the NFL, he could be ready to make his Oakland debut next month.Always turn a negative to a positive #Boomin— AB (@AB84) August 20, 2019The Raiders have two preseason games remaining before they host the Broncos in their regular-season opener Sept. 9.