GLENDALE, Ariz. -- The Arizona Cardinals are holding a couple of outdoor practices, then are going to do what many desert dwellers do this sweltering time of year -- head to San Diego.

The training camp usually is held in the air-conditioned comfort of University of Phoenix Stadium. But a Guns N'Roses concert forced the team outside for morning practices on Sunday and Monday.

After that, it's on to San Diego for joint practices with the Chargers on Tuesday night and Wednesday. Arizona and San Diego meet in a preseason game on Friday night.

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"Mike (Chargers coach Mike McCoy) and I have talked a bunch of times about doing it together," Cardinals coach Bruce Arians said. "Guys are tired of hitting each other. ... It's a good change of pace for us."

Arians didn't seem too concerned about Friday night's 30-10 preseason loss to Oakland. Cardinals starters played one series, with the exception of new starting right tackle D.J. Humprhries and rookie cornerback Brandon Williams, who played to the second quarter.

After viewing video of the game, Arians said there's "a lot of technique work that needs to be cleaned up with some younger players. But the effort was really good and we need to tackle better."

Arians said the starters will get, at most, 16 to 18 plays against the Chargers. He wants the starters to have gone about 50 plays in the preseason before Arizona opens its season at home against New England on Sept. 11.

Quarterback Carson Palmer called Friday night's brief stint by the starters "a tease" that made him want go play longer.

Arians said he's in no hurry.

"I'm pretty sure I know what they can do," he said. "It's just a matter of getting them all there to that first game."

Arians said defensive back Tyrann Mathieu (knee), cornerback Justin Bethel (foot) and defensive lineman Frostee Rucker (foot) -- could come off the physically unable to perform list in the coming week but only for walk-throughs.

They will "eventually get into individual drills, when they're ready," Arians said. "I can bring them off early, not necessarily because they're physically ready but to get some mental reps."

Arians said he's pleased with the team's overall progress.

"I think we're a little bit further along than we've been in the past," he said. "Obviously, our learning curve wasn't as step for our veteran players. The younger players, seeing the vets do it right, they get better exposure on how to do it, so they learn quicker that way."

All-Pro cornerback Patrick Peterson has been tutoring Williams all camp and said the rookie had a solid performance in a tough matchup with the Raiders' Amare Cooper.

"For the most part, I thought he had a very sound game," Peterson said. "His technique is getting better, his position as far as engaging the receiver has definitely gotten better. So he's definitely taking the right strides and he's got three more games to learn."

Arians singled out the play of tight end Troy Niklas, a second-round draft pick out of Notre Dame in 2014 who has been slowed by injuries his first two seasons.

"I thought Troy had a heck of a game," Arians said. "He put together a great week of practice and it showed up in the game. He continues to push those other two guys (Darren Fells and Jermaine Gresham) for the starting job."

Niklas said he's "feeling good."

"I feel a lot more competitive this year," he said.

Safety Tony Jefferson is from San Diego and said he's already been besieged by teammates with questions about the best restaurants.

"Everybody's asking `Oh, where do I go,'" he said.

Jefferson's reply: "Just follow my lead and I'll lead you to the promised land."

Notes: Gresham sat out Sunday's practice with back tightness. ... The Cardinals signed defensive tackle Iosia Iosia (yes, that's his name). Iosia is an undrafted rookie free agent out of West Texas A&M who was released by the Tennessee Titans on May 16. Arizona reached an injury settlement with linebacker Zack Wagenmann. ... Palmer's San Diego-area house remains on the market. The Los Angeles Times reported the asking price at $25 million.