Dietrich Riley out vs. Arizona State

UCLA safety Dietrich Riley will not play this week against Arizona State, but that was of secondary consequence to Riley, who spoke with reporters Wednesday for the first time since getting carted off the field Saturday during UCLA's victory over California.

"I'm just thankful to be here today and I'm just thankful I'm walking and alive," Riley said. "It could have been more severe so I'm just thankful the man above is watching over me."

Early in the fourth quarter against Cal, Riley fell to the ground limp after making a hit on running back Isi Sofele. He lay motionless for a few moments while trainers attended to him. He was moving his arms and legs by the time they stabilized his head and neck and carted him away for transport to Huntington Hospital, but said there were some scary moments while laying on the ground.

"I couldn't feel anything in my upper or lower body, but once the training staff came to check on me, that's when I began to get feeling back in my upper and lower body," Riley said.

The initial diagnosis was that it was a "stinger." Riley underwent an MRI exam and a CT scan, which all showed no significant damage. He has a second MRI scheduled for Thursday, but said it is just for precautionary reasons.

"At first I was a little sore," Riley said. "My shoulder was sensitive to touch. I had a burning sensation, but it's gone away. The training staff here has done a great job of helping me out."

As for when Riley will return to the field, he said that decision has yet to be made.

"We're just going to take it day by day," he said. "It depends what happens with the second MRI, but we'll see."

Peter Yoon covers UCLA for ESPNLosAngeles.com.