No head coach, no problem for the Arizona Cardinals on Sunday.

With Kliff Kingsbury home in Arizona after a positive COVID-19 test on Friday, the Cardinals kept their offense on track in a dominating 37-14 road win over the Cleveland Browns at FirstEnergy Stadium to improve to 6-0 and continue to their reign as the NFL's only undefeated team.

"I think once we got the news, it was just an opportunity," quarterback Kyler Murray said after Sunday's game. "Kind of exciting to go prove ourselves on the road against a great team. I think you could feel the energy before the game."

Losing Kingsbury and quarterbacks coach Cam Turner on short notice didn't affect the Cardinals much as they looked to continue their undefeated season. Assistant wide receivers coach Spencer Whipple was the voice in Murray's ear all game and called the passing plays while run game coordinator and offensive line coach Sean Kugler called the ground attack. Murray said Whipple was "calm, cool" and "didn't panic" during the game.

Defensive coordinator Vance Joseph, who shared the head-coaching responsibilities with assistant head coach and special teams coordinator Jeff Rodgers in Kingsbury's absence, said that was a result of Kingsbury having prepared his assistants over the years to call games like he would.

"We made him right," Murray said of Whipple. "Whenever he called it aggressively, we had all the faith. We were behind him, regardless of what he called it we're gonna go out there and execute."

Murray threw for 229 yards and four touchdowns, the second time in his career he's thrown that many, on 20-of-30 passing. The offense tallied 352 total yards while running for 144, including 42 on a clock-eating 7-minute, 18-second drive in the fourth quarter.

A.J. Green led Arizona in receiving with five catches for 79 yards and a touchdown. DeAndre Hopkins contributed three catches for 55 yards and two touchdowns.

Running back James Conner had 16 carries for 71 yards, and Chase Edmonds had four for 46.

"It was different in the sense of obviously Kliff not being on the sideline," said wide receiver Christian Kirk, who had five catches for 75 yards and a touchdown. "For me, when I was looking at the sideline and I did not see Kliff and it was definitely odd. But like I said, there were so many people who stepped up. In regards to how the game was called the game plan is the game plan. We all have a good feel in certain situations on what play is going to be called, and, obviously Kliff develops that and we practice it all week. So, Spencer did a good job of sticking to it, but also being able to change on the fly."

Joseph said Whipple and Kugler, who has head-coaching experience, talked through different calls.

"It was really seamless," Joseph said.

Murray said Kingsbury's absence gave him a little more freedom at the line of scrimmage to check in and out of plays.

"That may be a product of not having a coach out there, just having a little more leeway," Murray said. "I guess that did give me a little more freedom, just to whatever I did see, go with it and that's Whipple's saying to me the whole time: 'Whatever you see'. And I stick to that same rule, as long as it makes sense. You got a plan and go with it."

Defensive coordinator Vance Joseph, who shared the head-coaching responsibilities with assistant head coach and special teams coordinator Jeff Rodgers in Kingsbury's absence, said it was a "rough week."

"It's been an up and down week, but our team leaders were great all week," Joseph said. "No one wavered, no one blinked. The staff didn't blink. Every day it was bad news and no one blinked - not one time. Even yesterday. Even Saturday morning at practice when the players knew that Kliff was down for the game, there were no worries.

"There was really an excitement to go play a really good football team. The boys performed. This staff is amazing. It's a great football staff. It's our third year all together and that helps - having continuity like this."'

The Cardinals put defensive lineman Corey Peters on the reserve/COVID-19 list on Sunday morning, two days after having to put fellow defensive lineman Zach Allen on the list. However, the Cardinals' assistant to the head coach, Kenny Bell, had the idea to travel with an extra lineman just in case Allen's positive test resulted in others, so the Cardinals brought practice squad defensive lineman Jonathan Ledbetter with them. He was elevated to the active roster on Sunday morning and played nine defensive and two special teams snaps, according to NFL Next Gen Stats.

After getting tested on Friday, Murray, who turned in a negative test, made a comment to the rest of the quarterbacks as well as Turner, the quarterback's coach, that it would "suck if somebody gets it."

Joseph wasn't sure how Peters would travel back to Arizona but said he was "in good spirits and he is happy for the team." Kingsbury was asymptomatic as of Sunday morning, a source told ESPN.

The Cardinals' concern about COVID continuing to spread hasn't been curtailed.

"I think everyone is nervous about the COVID issues," Joseph said. "It is a moving target. Obviously, if you have one positive, there can be two or three more. I'm surprised there weren't more. Right now it's a moving target. We'll see what the league gives us this week as far as protocols.

"It speaks to our young guys and our reserve players who can step up and play for us. Everyone is dealing with this. We had our bad stint right now, but it's not going away."

Cardinals owner Michael Bidwill called Kingsbury on FaceTime after the win.

"He is fine," Joseph said. "He is happy obviously and he is at home recovering."