Frustrated Oakland Raiders fans aren't the only ones fed up with Antonio Brown's uncertain status as the regular season draws closer and closer.

During a Monday appearance on FOX Sports' Undisputed, James Harrison, his former teammate with the Pittsburgh Steelers, said that “it's time” for Brown to give up the helmet-related grievance that's most recently kept him off the playing field.

Harrison and Brown were teammates with the Steelers for eight seasons, emerging as two of the game's best players on either side of the ball while leading the Steelers to five playoff appearances. Harrison, the 2008 Defensive Player of the Year and a five-time Pro Bowler, retired after the 2017 season. He won Super Bowl rings with the Steelers in 2005 and 2008.

The Raiders acquired Brown from the Steelers in exchange for third and fifth-round draft picks earlier this offseason. Despite frequent clashes with quarterback Ben Roethlisberger and coach Mike Tomlin, Brown had another dominant season in 2018, finishing with 104 catches for 1,297 yards and a league-high 15 touchdowns.

Though the six-time Pro Bowler was thrilled at being traded to Oakland, he's barely taken the field for Jon Gruden's team ever since, first beset by a freak frostbite injury to both of his feet and then the league's insistence that he no longer wear his preferred helmet.

Brown was back at practice with the Raiders on Tuesday, but left the field when his teammates put on their helmets.

He later returned to action donning a league-approved helmet, though, causing Gruden to tell reporters that Oakland’s superstar receiver is “ready to go” and “all in.”