Bruce Arians' availability in question for Arizona Cardinals game vs. San Diego Chargers

SAN DIEGO -- Head coach Bruce Arians is feeling better but he still might be a little under the weather for Friday's preseason game in San Diego (9 p.m.) after being hospitalized overnight earlier in the week because of diverticulitis.

Arians was rushed to the hospital before Tuesday night's joint practice at Qualcomm Stadium after he doubled over in pain, thinking he was suffering from a kidney stone. It turned out to be complications from diverticulitis, an inflammation or infection in the colon, which was diagnosed during a recent colonoscopy.

He is on antibiotics and doctors have told him to make changes in his diet as well as drink lots of fluids.

"I've been on a pretty strict diet anyway, so it was odd that it happened," Arians said Wednesday, when he watched only 30 minutes of practice before returning to the team's hotel.

There was no media or coach availability on Thursday, so it wasn't known if there might be any chances to Arians' availability for Friday's game. Quarterback Carson Palmer isn't expecting Arians to miss the contest.

"If there's one thing guys in our locker room know," Palmer said, "it's that he's as tough as anybody in that locker room."

"He's going to be fine," wide receiver Larry Fitzgerald said. "We've got the toughest coach in the business."

-- Safety Tyrann Mathieu hasn't been cleared to start participate fully in practice, but now that he's been activated off the physically unable to perform list and is nearing a return following his second ACL surgery in three years, the Honey Badger said he's pumped to get going again.

"This is going to be fun. It's going to be a great year," Mathieu said. "We've got a great team. I've already got my goals listed, so I'm just ready to perform."

Asked to share some of those goals, Mathieu politely declined, saying, "I don't want to break the Internet."

-- Wide receiver John Brown is still in the concussion protocol and didn't make the trip to San Diego, where the Cardinals have spent most of the week in preparation for Friday's preseason game. Brown suffered a concussion when he hit his head on the field during the first day the team practiced in pads.

"There's always a concern when there's a concussion, but we're going to take our time until he's totally cleared," Arians said. "And then take a few more days, because he's got to get back in shape now. He's going to be totally out of shape."

-- Palmer said the two days the Cardinals spent practicing against the Chargers was beneficial if for no other reason than he finally didn't know what was coming from the opposing defense.

"I know the calls defensively because I've heard them over and over again," he said of facing Arizona's defense. "You know what coverage is coming. All their code words you start to memorize. It's refreshing to have a new look. It's refreshing to have different numbers. Having to go through all your protection adjustments with different guys in different spots and competing against a different style of defense, it's been great."

-- One of the best matchups to watch in camp has been among two backups - second-year nose tackle Xavier Williams and rookie center Evan Boehm. The two were Missouri high school rivals in football and wrestling and Boehm handed Williams his only two defeats during his senior year in wrestling. There's no bad blood between them, just a lot of daily competition in practice when they line up against the other.

"Oh yeah, we're buds," Boehm said. "X is the best, man. We're totally buds. You've got to be when you're all the way out here and you're from the same city. It's awesome to see how we got here, us going in different directions, being from the same city, growing up 10 minutes apart, him going to (Northern Iowa), myself going to Missouri, and then ending up on the same team.

"It's a small world when that stuff happens. We talk about it a lot. It's pretty cool having a kid from the same area as you, a kid you competed against already, being on the same team. Just knowing how competitive he is and the battles we had, and now going against each other on the offensive and defensive line. It's a lot of fun."

NOTES: Mathieu will wear a brace on his right knee, but it's smaller and lighter than the one he wore on his left knee in 2014. "Any brace, there is some restriction to it," he said. "But this one is way lighter and this injury is not as severe as the last one." ... DT Robert Nkemdiche, the Cardinals' first-round pick this year, is expected to make his training camp debut next week after suffering a high ankle sprain upon reporting to camp, Arians said. ... TE Jermaine Gresham returned to practice after being limited for a few days because of back tightness. ... S Tony Jefferson said the team took Arians' disdain for fighting in camp to heart. Jefferson said there was no way any Cardinals players were going to take swings or cheap shots at Chargers players during two joint practices. "I don't think there's anything to be said," Jefferson said. "B.A. doesn't roll with that so that's just what we've got to do. Turn the other cheek."