MANKATO - The Vikings asked head athletic trainer Eric Sugarman during the offseason to put together a list of NFL defensive backs who have bounced back from tearing anterior cruciate ligaments in both knees and resumed their careers at a high level.

Sugarman said it ended up being a rather short list gleaned from the NFL's database. Short as in zero. Zip. Nobody.

"It's a different era," said Vikings coach Leslie Frazier, whose career as a cornerback ended with a torn ACL during the Chicago Bears' victory in Super Bowl XX. "When I tore my ACL, that was a career-ending injury. Guys just weren't coming back."

The Vikings think they will have the first defensive back to successfully come back from not one but two ACL surgeries in consecutive seasons when right cornerback Cedric Griffin returns to game action as early as the second preseason contest in Seattle. Griffin tore his left ACL in the NFC Championship Game on Jan. 24, 2010, returned nine months later to start Week 3 against the Lions and then tore his right ACL in Week 5 at the Jets.

"I never seen a raw deal like the one he's gotten," middle linebacker E.J. Henderson said.

Wait a minute. When it comes to raw deals, what about you, E.J.? After all, how many NFL players have broken a femur, let alone broken one while being inadvertently hit by a teammate?

"Really, my injury doesn't compare to his," Henderson said. "He's a corner going down with two ACLs and now he's back again like nothing happened? I've never seen somebody with so much resolve. I look at the injuries I've had, but this guy, the way he bounced back from not only one ACL but a second one like it was no sweat. My hat's off to him."

Hats off to modern medicine as well.

Frazier remembers being in the hospital 25 years ago and hearing the surgeon tell him that rapid advancements in ACL surgeries were coming. Unfortunately for Frazier and a lot of former NFL players, their knees were blown up at the wrong time in the history of sports medicine.

"Back then, I was in a cast for six weeks," Frazier said. "Now, they don't even cast you anymore. They start rehab prior to the surgery and then postsurgery they've already begun that constant movement, which is what you need to get that flexion back. It's a different operation today than it was back then."

Griffin is walking proof. Actually, he's running proof because he's moving fluidly with just a light sleeve over his right knee. The Vikings limit his reps in training camp, but they are counting on him being their starting right cornerback on Sept. 11 when they play at San Diego. If it happens, Griffin will have torn both ACLs and made two comebacks in a span of 20 months.

"I went through 18 months of rehab trying to come back," Frazier said. "Never regained my full range of motion."

Griffin said he has no doubts that he will be starting in San Diego. He has no doubts he will be the player he was in 2009, when he had a team-high four interceptions, forced three fumbles and had 78 tackles.

He has also grown extremely weary of the same questions about his knees.

"I'm fine," he said. "People keep asking me the same questions, but I'm doing fine. Honestly, my knees feel as strong as they were before the injuries."

Griffin said he has never been interested in any lists of players who have come back from tearing both ACLs.

"No one else can help me get through this," he said. "This is a new age of technology, a new age of medicine. As long as you listen to your doctors and your training staff, you'll be OK. But I'm the one who has to work hard. And I've just been blessed to have a strong mental mind right now."