Cardinals could go conservative vs. 49ers

Carson Palmer was ruled out of Thursday's game by the Arizona Cardinals, who must ask backup quarterback Drew Stanton to deliver a road win at San Francisco and keep the team from an unexpected 1-4 start.

Palmer entered the week in concussion protocol, leaving the Week 4 loss to the Los Angeles Rams with a head injury Sunday. The short week left little time for manipulating the Cardinals' game plan against familiar NFC West foe San Francisco. The 49ers (1-3) have quarterback questions of their own.

Arians said Tuesday before the team packed for Santa Clara, Calif., that his plan would not change much with Drew Stanton behind center Thursday.

"Yeah, not really," he said. "I think the mindset is the same."

Wide receiver Larry Fitzgerald said the Cardinals are confident in Stanton based on past performance. He went 5-3 in 2014 when Palmer was sidelined by a torn ACL.

"We have to keep playing. We have to keep fighting," Fitzgerald said.

The Cardinals might go a bit more conservative -- Arians admits this is counter his typical approach -- and ask its defense to flex its muscles. That includes cutting loose hybrid safety Tyrann Mathieu, who said this week he's ready to return to his Honey Badger role and plans to play more in the slot and closer to the box Thursday night against the 49ers.

That will certainly get the 49ers' attention, according to 49ers quarterback Blaine Gabbert.

"Yeah, you always got to be aware of where he is on the football field," Gabbert said. "He's a talented, instinctive player that makes a lot of plays on the ball. You have to be aware of where he's lining up, whether he's in the slot or he's back at safety."

The Cardinals have nine takeaways, second only to the Kansas City Chiefs (10), including five interceptions. Gabbert, who has just a 73.1 passer rating with four interceptions, is fighting to keep a hold on the starting job when Colin Kaepernick is deemed healthy. Kaepernick had offseason shoulder surgery and coach Chip Kelly said last week health is still holding Kaepernick back.

Some picked the Cardinals to represent the NFC in the Super Bowl -- notably, Sports Illustrated tapped Cardinals-Steelers for Super Bowl LI in Houston -- but getting out of the West division will not be easy. Seattle is 3-1 and the Rams got a leg up on Arizona with a head-to-head win Sunday. That game turned on a punt return on which Arians felt Los Angeles could have been penalized.

Not he's fearful his club will allow one painful loss to multiply.

"Well, you don't have a choice but to get past it. If it were a normal week, they could brood until they showed up Wednesday," Arians said.

Among other changes to the depth chart, the Cardinals are sliding Andre Ellington to the No. 2 running back spot after Chris Johnson was placed on injured reserve this week. David Johnson leads the NFL in yards from scrimmage and remains entrenched as the starter. Already accounting for more than one-third of the Cardinals' total offense, David Johnson could get a big workload Thursday night as the 49ers' defense begins finding its way without inside linebacker Navorro Bowman (Achilles tendon), who was also placed on IR this week.

The 49ers are also going without first-round pick DeForest Buckner (foot) and cornerback Jimmie Ward (quadricep), who were ruled out Wednesday.

Protecting Gabbert with balance has become Kelly's M.O., and running back Carlos Hyde has a league-leading five rushing touchdowns in four games. While the 49ers are 32nd in the NFL in passing, teams have not been able to stack the line to stuff Hyde, and San Francisco is converting 40 percent of third downs.

The deep speed of wide receiver Torrey Smith keeps most defenses on their toes, even if his season stats -- nine catches, 106 yards, one touchdown -- don't tell that story.

"A lot of it just depends on how people play us," Kelly said. "We've gotten a lot of man coverage out there, and sometimes people are leaning safeties toward his side, so we're taking advantage of what's going on."

Slot receiver Jeremy Kerley sustained a somewhat minor ankle injury in the Week 4 loss to Dallas and is questionable for the Thursday game against the Cardinals. He has a team-high 18 receptions and could draw Mathieu if the Cardinals employ their preferred nickel package.

"It definitely will get us back in the thick of things of our true identity," said cornerback Patrick Peterson of Mathieu. "The nickel position is a huge play-making position for us, and to have a guy of his caliber back at the position definitely is something that can help our defense. Is he ready? We'll see. Only he will know that. I'm excited to see him back in his normal role."

Like the Cardinals, the 49ers are dealing with some key injuries.

Tight end Vance McDonald has been limited in practice this week as he attempts to return from a hip injury that kept him out of the loss to Dallas. McDonald had a career-high six catches for 71 yards and a touchdown the last time he faced the Cardinals, on Nov. 29, 2015.