Adrian Peterson didn't like anything he saw during the Vikings' 39-10 meltdown in Chicago last Sunday. It wasn't just the dropped passes, missed blitz pickups and costly penalties. What frustrated Peterson just as much was how many Bears defenders he saw crowding the line of scrimmage every time the Vikings broke their huddle.

"They had nine, 10 men in the box -- from the first quarter through the fourth quarter," Peterson said. "What we have to do differently is be more productive in the passing [game] to be able to keep the defense off-balance and make them stay honest."

Not exactly a ringing endorsement for Donovan McNabb. And while Peterson later took the politically correct route and said McNabb got a raw deal in being benched this week in favor of Christian Ponder, the Pro Bowl running back also made it clear he can't wait for the day opposing defenses can't zero in exclusively on stopping him.

Peterson managed only 39 yards on 12 carries at Chicago.

"When a defense is focused on just stopping the run and being able to attack and basically daring you to pass because they don't believe you can, it's going to be a long day for you," Peterson said.

Injury update Receiver Percy Harvin and right tackle Phil Loadholt returned to practice Thursday after sitting out Wednesday because of injuries. Harvin is still dealing with sore ribs and Loadholt is keeping an eye on his swollen right knee, an injury he said occurred in the first quarter against Chicago when he planted wrong.

Both players believe they will be OK to start Sunday against Green Bay.

Center John Sullivan and safety Jamarca Sanford were both held out Thursday for the second consecutive day. Both starters suffered concussions against the Bears and will continue to be evaluated. NFL regulations require both players be tested by a third-party doctor before they can be cleared to play.

Testing the limitsAfter missing the past two games because of a neck injury, cornerback Antoine Winfield has been back at practice this week as a limited participant but is being given a yellow light for Sunday right now.

"The fact that he's trying is a good sign," coach Leslie Frazier said. "But we're not sure until we see him work out [Friday] how we'll list him for the game."

Winfield might not get a true assessment of his recovery until he's back in full-contact situations, which rarely materialize at practice. The stiffness in his neck is subsiding but still present.

"It's less than it was two weeks ago," Frazier said. "But not to the point where he's able to say, 'I'm ready to go and play the kind of football I'm comfortable playing.'"

Ponder watch For all the excitement that has surfaced about Ponder making his first start Sunday, quarterbacks coach Craig Johnson issued an eight-word warning of what's ahead in the immediate future.

"Listen now," Johnson said. "There's going to be some ugly."

Johnson remains as excited as anyone about Ponder taking over for the long haul and thinks he and offensive coordinator Bill Musgrave have expertise in developing young quarterbacks. In Tennessee in 2006, Johnson helped mold Vince Young into the Rookie of the Year. Two years later, Musgrave did the same thing in Atlanta with Matt Ryan.

Quotes of note With so much talk centered around Ponder's mobility, Peterson was asked how the rookie's speed compared.

"Compared to me?" Peterson responded with wide eyes. "I don't know. It's kind of like a rabbit and a turtle."

Musgrave, meanwhile, addressed Ponder's need to study extra long this week.

"We're definitely tempted to burn the midnight oil. And we always do as coaches," Musgrave said. "But we don't want to wear him out and cause him to leave his game in the bullpen either."

Etc. • After running back Lorenzo Booker and receiver Devin Aromashodu helped ignite the Vikings offense in a 34-10 blowout of Arizona in Week 5, talk surfaced of getting both players more involved. In Chicago, however, Booker carried the ball only once, stopped for a 3-yard loss. Aromashodu was held without a reception, targeted only twice.

• If Sanford were unable to play Sunday, Tyrell Johnson would start in his place. Defensive coordinator Fred Pagac would also consider activating rookie Mistral Raymond for the first time.