Mathieu tore the anterior cruciate ligament and lateral collateral ligament in his left knee last December.
Mathieu made six total tackles in Arizona’s 23-14 victory over San Francisco and has only seen 20 snaps this season.
"I thought I was playing a little lackadaisical in my technique," Mathieu said, according to the Arizona Republic. “Things I wouldn't normally do. I'm still a few weeks away from being the guy I want to be. That confidence is going to come, just with more playing time."
Mathieu said he hopes to improve by the time the team’s plays the Denver Broncos on Oct. 5. The Cardinals are off in Week 4.
- Scooby Axson