SANTA CLARA The consensus among the 49ers after watching recent game film of the Minnesota Vikings: Adrian Peterson must have magical healing powers.
How else to explain how the four-time Pro Bowl running back suffered a torn ACL and a ruptured MCL less than nine months ago and yet looked as strong as ever in his first two games. Peterson started in Weeks 1 and 2, and all indications are that his carries will be ramped up today against the 49ers' vaunted run defense.
"He's one of these men who have superhuman powers of recovery," 49ers coach Jim Harbaugh said. "And tip of the hat to him. And you know how hard he must have worked and trained to get back to the level he's at. But this is a great challenge for our team."
Five minutes later, Justin Smith sounded eerily similar to his coach when asked about Peterson.
"That guy is a miraculous healer," Smith said. "I mean, he's out there making cuts and looks just as fast as he ever has. Hat's off to him. I know all the work he put in in the offseason must have been ridiculous to get to where he's at right now. It will be a good challenge."
Of course, the 49ers aren't exactly quaking over the prospect of facing Peterson and No. 2 runner Toby Gerhart, who had 11 carries over the first two weeks.
San Francisco had the league's stingiest run defense a year ago, shutting down acclaimed tailbacks such as Philadelphia's LeSean McCoy and Baltimore's Ray Rice and keeping runners out of the end zone until Week 16.
What's more, the 49ers finally will be able to use their base defense with nose tackle Isaac Sopoaga after primarily using nickel and even dime packages in wins over pass-centric Green Bay and Detroit.
Peterson says he's eager to test himself against the 49ers and to get another crack at the player he considers to be the second-best prospect in the 2007 draft.
"I don't know why me and him weren't the No. 1 and 2 picks coming out," Peterson said of 49ers linebacker Patrick Willis in a conference call on Wednesday. "I really thought that way. I know talent when I see it."
Peterson and Willis have played each other twice since they entered the league together in 2007 they share the same agency and went through the predraft process together with the Vikings winning both games.
During their rookie season, Willis and the 49ers' defense held Peterson, the eventual Offensive Rookie of the Year, to three carries for 14 yards. That 0.2-yard rushing average is by far Peterson's worst NFL performance.
In 2009 in Minneapolis, the game in which Brett Favre beat the 49ers on a last-second touchdown pass, Peterson rushed 19 times for 85 yards.
Peterson said he has bad memories of one hit in particular, which came during the 2007 game.
He said it happened on an inside zone run to the left during which he encountered Willis in the hole and was knocked backward for a loss.
Peterson conceded that Willis "got me on that one."
In Peterson's mind, however, there should be an asterisk next to the hit.
He said Willis had the advantage because he hit Peterson while Peterson was cutting.
"You can't cut and lower your shoulder and think you're going to run him over," Peterson said. "Some guys you can get away with it. But he's a different person, a different player. That's not happening."
Willis was quick to point out that it won't be a one-on-one matchup between him and Peterson when the Vikings have the ball. The 49ers' run defense excels, he said, because everyone is involved.
Running backs know that if they break one tackle, "there's 10 others coming," Willis said. "We take pride in that."