It appears the Cardinals will play the final three games of the season without rookie Tyrann Mathieu, who suffered a left knee injury while returning a kick in the third quarter.

The Cardinals fear Mathieu suffered a torn ACL, which would require surgery and rehabilitation of six to nine months.

“He’ll go through the MRI and the rest of the tests and we’ll just keep our fingers crossed,” coach Bruce Arians said.

Mathieu was on the field because the Rams were punting after the Cardinals scored a safety to take a 23-3 lead.

“I just wish that he’d (Johnny Hekker) kicked that damn ball to Patrick (Peterson),” Arians said.

A third-round pick, Mathieu has been sensational as a rookie. He moved into the starting lineup at free safety six weeks ago, and has played cornerback in nickel and dime packages all season.

He lost 5 yards on the return and it appeared his knee twisted when he was tackled. He collapsed as he trotted to the sideline.

“He’s been bawling since he’s got the news,” cornerback Jerraud Powers said. “It’s going to be a huge blow. I just feel bad for him. Guys like him and Patrick, football is the world and more to them. He (Mathieu) really feels blessed just to be on the field.”

Powers said the Cardinals have the depth to compensate. Rashad Johnson has starting experience at safety and the Cardinals have experienced backup cornerbacks in Antoine Cason and Javier Arenas.

“The extra dimension Ty brought to the table is when we were in regular personnel, sometimes we didn’t have to bring in an extra (defensive back),” Powers said. “We’ll probably have to find a few ways to take care of that.”

Outside linebacker John Abraham said the Cardinals will miss Mathieu’s passion.

“My thing is it’s more about his personality, his urge and his mentality on the field,” Abraham said. “Even though he’s a young guy, he prepares like a vet and he acts like a vet. I think that’s one of the biggest things we’re going to lose.”