Cardinals running back Chris Johnson injured his groin Sunday against the Rams and now is headed to injured reserve.
The Rams' loss hurt the Cardinals beyond the standings.
For a second straight year, running back Chris Johnson is headed to injured reserve after hurting his groin Sunday, and safety Tyvon Branch is going on IR for the same injury.
Depending on the severity, one of the two could still come back. Teams don't have to declare who is on
IR-to-return, as long as that player sits out eight weeks.
"I'd like to have more than one," said coach Bruce Arians, who said which player returns likely depends on their recovery from the same hernia surgery.
If one returns, the first game he would be eligible to play would be Dec. 4 against Washington.
The moves come as the Cardinals try to stabilize the roster heading into Thursday night's game against the 49ers. To replace Johnson on the roster, the team re-signed running back Kerwynn Williams, who was released at the end of the preseason.
With the status of concussed Carson Palmer uncertain for the game, the Cardinals also promoted quarterback Zac Dysert from the practice squad. To make room on the roster – and with Ryan Quigley currently punting -- the team waived punter Drew Butler (calf) with an injury settlement.
Butler could also return later in the season if the Cardinals so chose.
The Cardinals also promoted wide receiver/defensive back Brittan Golden from the practice squad to the active roster. They signed safety Christian Bryant to the practice squad, and still have a practice squad opening.
Without Branch, the need for Tyrann Mathieu – who talked Monday about the urgency of getting back into
his role of slot cornerback – to play the slot becomes more important.
"It definitely would get us back in the thick of things as far as our true identity," cornerback Patrick Peterson said.
With Johnson out, Andre Ellington now moves into the backup role behind starter David Johnson.
"(Chris) is such a dynamic player," Arians said. "It just gives Andre Ellington another chance to get more reps. We're not afraid of giving the ball to Andre, that's for sure."
"I'm ready to go whenever Coach needs me to go," Ellington said.
Arians added that with the running back situation, Ellington will likely not return kickoffs. That role could fall to Williams, Golden or J.J. Nelson, all of whom have done it in the past.
Johnson had 95 yards and a touchdown on 28 carries. Ellington has only two carries this season, for two yards, although he said he understands his role.
"A guy like Dave, he was getting the job done," Ellington said. "I'm a team guy, so if he's getting it done, I'm over there applauding him and making sure he knows what's going on at all times, when he comes to the sideline and is asking about different looks."
PALMER REMAINS IN CONCUSSION PROTOCOL
Arians said Palmer attended meetings Tuesday but otherwise remained in concussion protocol. Asked if there was a chance Palmer could make the road trip and have a decision made on his playing status Thursday, Arians said he was deferring to the doctors.
Tight end Darren Fells (shoulder) and defensive tackle Ed Stinson (toe) did not practice. Defensive tackle Josh Mauro (chest), defensive tackle Frostee Rucker (knee), tackle D.J. Humphries (knee) and cornerback Justin Bethel (foot) were limited.
For the 49ers, defensive tackle DeForest Buckner (foot) and cornerback Jimmy Ward (quad) did not practice. Wide receiver Jeremy Kerley (ankle), guard Zane Beadles (ankle), cornerback Chris David (quad) and tight end Vance McDonald (hip) were all limited.