"He's going to tackle somebody this week," Arizona coach Bruce Arians said.
Only after Mathieu tackles in practice will Arians decide if the Honey Badger will play Sept. 8 against the San Diego Chargers at University of Phoenix Stadium. Mathieu returned to practice Aug. 20, almost nine months after suffering an ACL and LCL injury in Week 14 of the 2013 season.
It took him a day to progress from individual defensive back drills to working with the scout team, but he didn't engage in contact. Mathieu was held out of the final two preseason games.
Throughout the past week Arians has maintained that Mathieu wouldn't play in Week 1 if he didn't play Thursday night in San Diego.
"I wasn't kidding," Arians said. "We'll see how he tackles.
Asked who'll be the lucky teammate to take the brunt of Mathieu's hits next week, Arians was ready with an answer.
"That's what practice squad is for," he said with a laugh.