Campbell said he'll be evaluated by team doctors sometime between arriving at University of Phoenix Stadium at around 3 p.m. and kickoff which is scheduled for 5:25 p.m. He is unsure of what the doctors are looking for or what kind of drills they'll put him through.
"As long as I feel ready on game day I'm going to go out there and play my best," Campbell said. "It's a big game, prime time, division game. A game that we need to win. A game I really want to play in as [long] as I can feel like I can protect myself and go out there and show it to doctors, prove it to the doctors."
Campbell suffered a "bruised spine," according to Cardinals coach Bruce Arians, during Sunday's 32-20 loss to the San Francisco 49ers. He was carted off the field on a stretcher and taken by ambulance to Stanford Hospital, where he underwent a battery of tests before being released late Sunday.
Arians said Tuesday night on SiriusXM NFL Radio that he was optimistic Campbell would be ready to play. When the final injury report was released Wednesday, Campbell was listed as questionable.
"I feel pretty good. I feel healthy," Campbell said. "The biggest thing is just making sure I can protect myself. Anytime you're out there playing football, you've got to be able to protect yourself and as long as I'm confident that I can do that, I'm going to play football."
Protecting a football player has become the most heated debate in American sports, especially when it comes to head and neck injuries. But Campbell, who momentarily lost feeling in his arms and legs Sunday, said protecting himself starts with using his hands and good technique such as keeping his head up and hitting with his shoulders.
Campbell wouldn't let on if his neck and back were still bothering him, just that he had the aches and pains that come with playing the game. While he waits until Thursday afternoon, Campbell is ready to strap on a helmet.
"He's been fine," Arians said Wednesday. "And looks like he's ready to go."