ENGLEWOOD, Colo. -- Shortly after playing in the Oakland Raiders' 59-14 rout of Denver on Sunday, Broncos rookie cornerback Perrish Cox went home and watched the contest again.

Not to learn what went wrong.

Just to remember what took place after a blow to the head completely wiped out his memory of the game.

Cox suffered a head injury in the third quarter and couldn't recall any of the details from the lopsided loss. He clearly remembers the night before and then coming to in the trainer's room.

In between, nothing.

"I woke up and asked what the score was and they told me, 'A lot to a little,' " Cox told The Associated Press on Tuesday. "That was kind of shocking to me -- I don't remember nothing."

Later, Cox fast-forwarded the game to the play where he was injured. He had to know what happened.

But Cox saw nothing out of the ordinary.

One moment he was hovering around Raiders receiver Louis Murphy near the sideline on a pass play and the next both were down on the field. Murphy left the game with a chest injury and Cox was helped to the bench and then into the locker room.

"I think I caught his back or a knee or something like that," Cox said. "But I was out."

He tried to finish watching the recording of the game but couldn't, quickly switching it off.

"I deleted it," Cox said. "I don't even want to see it no more. Get well and just forget about it. I don't want to think about it."

Cox showed up Tuesday wearing dark shades to shield his eyes from the bright lights in the locker room. Cox said he has never had a concussion before and used to wonder what all the fuss was about.

With his head pounding, he now understands.

"I looked at it as just a head injury. When it happened to me and I forgot everything, it makes you nervous," Cox said. "You feel like you got knocked down. But you got knocked down a few levels. It still scared me because I don't know what happened."

Cox hasn't been officially ruled out for when the Broncos (2-5) travel to London to face the San Francisco 49ers (1-6) on Sunday. He didn't practice Tuesday but arrived at the facility so he doesn't fall too far behind in preparations -- just in case.

He still has to pass the NFL-mandated post-concussion test before he can play.

"I was told there was a chance," said Cox, a fifth-round pick out of Oklahoma State who has been starting opposite Pro Bowler Champ Bailey due to injuries in the secondary. "A lot of players come back in three to five days. My goal is to try to come back as quick as I can."

Broncos coach Josh McDaniels said the team will take a cautious approach.

"He got dinged in the head so we're going through that whole procedure," McDaniels said. "Make sure we make a real smart choice on whether to travel him or not. We won't know that for a few days here."

Might his head injury be affected by the flight to London?

"There's some things I'm sure that are impacted [with air travel]," McDaniels said. "That's one we'll treat very seriously and go through all the precautions we need to and try to make a real smart decision."

Although Cox sat out of practice Tuesday, the Broncos had cornerback Andre' Goodman (thigh) and emotional leader Brian Dawkins (knee) on the field for the portion the media was allowed to view. Both have missed the last two games.

It's an encouraging sign as the Broncos try to forget the fiasco against the Raiders, who set a franchise record for points.

"We did maybe one or two things good out of 85 or 90 plays on defense," Bailey explained. "We've just got to tighten things up. Nobody has their head down around here. It was tough, obviously, but we've got to move on. We've got another tough team to face this week."

And Cox is hoping to be along for the ride. He said he's taking prescription medicine to help ease the headaches.

"Doc told me whenever I'm at home, sit and rest in the dark, watch movies," Cox said. "I plan on playing this week. I'm going to come up and get as much coaching as I can, watch as much film as I can and also get the treatment."

Still, he won't rush back, especially after losing a stretch of his memory.

"That's what makes you nervous about it," Cox said. "You don't know how you're going to come back from it -- if it's going to bother you in the long run or can this happen again?

"I don't want that to happen again," he said.