Peterson, who has been fitted with a brace for his injured right knee, practiced on a limited basis in the days leading up to the Vikings' surprising 41-17 victory over the host New York Giants last Sunday. He then did extensive work on the field in the pregame warmups before it was decided that he would not play.
The rookie phenom tore the lateral collateral ligament in the Vikings' 34-0 loss Nov. 11 at Green Bay. The good news was he did no damage to any other ligaments and the Vikings immediately made it clear the injury would not end Peterson's season.
Despite missing the Vikings' victory over Oakland on Nov. 18, Peterson still entered Week 12 leading the league in rushing with 1,081 yards in nine games.
The seventh-overall pick in the NFL Draft last April, Peterson's return to the field should all but wrap-up Offensive Rookie of the Year honors for him. If he didn't already have the award won.
Peterson admitted if it was up to him he would have returned at Giants Stadium.
"Actually, I felt good," he said after the game. "It's all about them having ... we have to practice and really going through everything. Being able to get that comfortable with the looks and different things like that. Practices and game speed are totally different.
"... (But) once I get a full week of practice under my belt then I'm pretty sure I'll be ready to play. We're just going to continue to take it one day at a time. Each day I've been improving, so try to keep it up."
While Peterson's return appears likely, it's uncertain how much longer cornerback Antoine Winfield will be out. The veteran missed a game for the third time in four weeks last Sunday because of a hamstring injury.
He originally suffered the injury Oct. 28 against Philadelphia and sat out the next two games. That was notable because Winfield had not missed a game since his first year with the Vikings in 2004.
He returned against the Raiders but only played the first half before departing. Winfield did not practice last week and was replaced again by rookie Marcus McCauley as the starter at New York.
That looked to be a severe blow considering the Vikings entered last weekend's game ranked last in passing defense. However, with McCauley and second-year corner Cedric Griffin starting at the corners the Vikings only gave up one touchdown pass and that came late in the fourth quarter with the Vikings holding a big lead.
McCauley, meanwhile, is getting some valuable on-the-job training. He began the season as the Vikings' nickel back but lost that job in the same game in which Winfield hurt the hamstring.
Since that time McCauley has started three of four games and seen extensive playing time in all four. That total could reach five games next Sunday against Detroit.
No one has ever questioned Winfield's toughness — at only 5-feet-9 he is one of the NFL's hardest hitters — but there is no doubt the Vikings and Winfield aren't going to have him rush back and possibly suffer a season-ending injury.