EDEN PRAIRIE, Minn. Through eight months of rehab for a torn ACL, Adrian Peterson couldn't think of anything more than getting the chance to run the ball in a game again. Now that he has returned to the field, the Minnesota Vikings' top running back knows he can't do it alone.Preparing for Sunday' game at home against the stout San Francisco 49ers run defense, Peterson said Thursday he continues to improve in his comeback from knee surgery and is hoping for a balanced offense against San Francisco, which led the league in rush defense last year and is sixth through the first two games this season."Yeah, I'm sure they'll come in and focus on trying to stop the run," Peterson said. "That's where we've just got to be productive offensively, keep those guys honest; complete some balls down the field and still run the ball. We've got a job to do, and I feel like if we're able to execute our game plan then we should be OK."Peterson surprised many by running 17 times for 84 yards and two touchdowns in the season opener after not playing at all in the preseason. He was limited to 60 yards on 16 carries by Indianapolis in Week 2 as coach Leslie Frazier said a two-touchdown deficit in the second half took Peterson out of the game.San Francisco has faced two pass-oriented teams, the Green Bay Packers and Detroit Lions, on the way to a 2-0 record. In fact, with the 49ers as one of the favorites to represent the NFC in the Super Bowl, they represent the prototype Frazier has said he'd like to establish in Minnesota: a mistake-averse run-first offense combined with a strong defense.Peterson believes San Francisco can pass the ball, too, which is just the type of balance he'd like to see with the Vikings."It goes hand-in-hand," Peterson said. "That's the type of offense we need, too. I don't feel like we can just stack up and run the ball every game, especially against a defense like this. I don't think it will go too well. I think you've got to be able to do both."One benefit to a balanced offense would be Peterson facing fewer defenders at the line of scrimmage. Peterson has been the focal point of Minnesota's offense for the past five years and said he's always seen the eight- and nine-man fronts designed to stop him.That hasn't changed even as he returns from a serious injury."We saw it last week against Indy," Frazier said. "The first ballgame we got more two-high safety, which we were surprised that they would defend us that way and I'm sure it was partially because of Adrian coming back and not being certain of where he was. As the game went on, that philosophy changed in the first game and for sure against Indy it was a lot more eight-man fronts as the game went on."He's coming along, and I think people are to the point right now where they're saying, You know what? We have to make sure we're defending 28.' "Meanwhile, Peterson keeps working his way back. He wouldn't put a grade on his health but said for the second straight week that he will gain a little more explosiveness in the months ahead."Yeah, I feel like there's another gear I can get to, but each day I feel I'm getting stronger and getting closer to where I want to be," Peterson said. "I'm just going to keep pushing at it."
Henderson's status in doubt with concussion: Frazier offered some clarity on linebacker Erin Henderson's concussion Thursday, with Henderson missing his second straight day of practice.Henderson left Sunday's game at Indianapolis after getting hit while trying to make a tackle. He later returned, and Frazier said there were no signs of a concussion during the game. After two days, Henderson started to feel symptoms and was given a concussion test before Wednesday's practice."There was nothing to indicate that something was going on until he came out Wednesday," Frazier said. "That's when they decided, You know what? We need to take him through the concussion protocol.'"Wednesday he came out to practice and just didn't feel right."Henderson will have to pass concussion-related tests before being able to play on Sunday against the 49ers, and Frazier wasn't sure if he would be ready.If Henderson is unable to play, Marvin Mitchell likely will start in his spot as the weakside linebacker in the base defense. Middle linebacker Jasper Brinkley would stay on the field in the nickel defense. Mitchell has been inactive for the first two games while trying to recover from an ankle injury.Follow Brian Hall on Twitter.