NAPA, Calif. – Antonio Brown celebrated his first training camp with the Oakland Raiders by taking a hot air balloon ride over the Napa Valley.

Coach Jon Gruden thought it was tame by the flamboyant wide receiver's standards.

"I expected a little bit more than a hot air balloon," Gruden said Friday. "I thought he might jump out of an airplane and parachute here himself. He's going to add a lot of life to this organization at a position where we need some explosive plays."

Brown actually arrived late Thursday while the remaining veterans checked in Friday, three days after rookies showed up to get a head start on camp.

But the 31-year-old was placed on the non-football injury list and will not be on the field for the team's first practice Saturday. The Raiders did not specify what Browns' injury was.

The Raiders will spend a little more than three weeks at the picturesque facility preparing for their final season in Oakland ahead of their move to Las Vegas in 2020.

Entering the second year of his second stint with the Raiders, Gruden said his team has a lot to accomplish to improve upon a 4-12 finish in 2018.

"We are very confident that we've taken some really good steps in building our football team," Gruden said. "We need some veterans to come through and we need some young guys to come through. We feel like we've gotten faster, we feel like we've gotten bigger. We've got a lot to prove, that's for sure."

The Raiders are banking on a nucleus of veterans and a large group of younger players led by three first-round picks in this year's draft: defensive end Clelin Ferrell, running back Josh Jacobs and safety Johnathan Abram.

"You see the fact that not only did they show up in shape, they also showed up (and) had their heads in the frikkin books," general manager Mike Mayock said.

The Raiders have a list of issues to address in the coming weeks. Richie Incognito's two-game suspension has left a void at left guard; there could be as many as three new starters in the secondary; and the team made a bevy of changes around quarterback Derek Carr.

"We've got a lot of change around him, hopefully for the better," Gruden said. "He has done a great job not only with the system, he's done a great job leading the group. He's clearly established himself as not only an excellent quarterback but a premier leader on this team."

A lot of attention will be focused on Carr's relationship with Brown, the colorful, four-time All-Pro receiver whose finish in Pittsburgh was punctuated by a feud with Steelers quarterback Ben Roethlisberger.

"I expect a lot more drama from number 84, I really do," Gruden said. "I told Antonio, 'Try not to yell at Derek, yell at me when you have a problem.' Then he started yelling at me. I said, 'Don't yell at me, yell at (Greg) Olson, he's the offensive coordinator.'"

There were more than players and coaches wandering the halls of the Marriott Hotel on the eve of the Raiders' first training camp practice Saturday. HBO's 'Hard Knocks' is chronicling the team throughout camp, meaning extra cameras and people on the field and in meeting rooms.

"Jon and I are kind of old school, and the reason you go away to training camp is to get away from all the distractions, get together, bond, learn your assignments, no distractions, no intrusions," Mayock said. "Hard Knocks is an intrusion but it was handed to us. So it's up to us to deal with it and I think we're dealing with it in a professional way."

The Raiders don't have a full squad in camp. Left guard Denzelle Good will begin the year on the physically unable to perform list after undergoing lower back surgery five weeks ago. Fullback Keith Smith joined Brown on the non-football injury list with a knee injury he suffered working out in the offseason.