SANTA CLARA -- Chicken noodle will be the soup du jour Sunday at Lambeau Field, where the temperature is expected to drop below zero when the 49ers and host Green Bay Packers meet in an NFC wild-card playoff game.

Asked Wednesday how he prepares for such weather, Packers quarterback Aaron Rodgers replied: "Eat a lot of chicken noodle soup." When that tip was relayed, 49ers linebacker Patrick Willis replied: "Chicken noodle soup's pretty good. I can't argue with that one."

Willis then changed his order -- to alphabet soup, if you will.

"Just get me a 'W' and that'll give me all the warmth I need," said Willis, who practiced Wednesday in shorts amid 61-degree weather.

The National Weather Service forecasts a high near 8 at kickoff Sunday, with the temperature dropping below zero during the game.

In coach Jim Harbaugh's three seasons, the 49ers (12-4) haven't played in a game in which the kickoff temperature was colder than 34 degrees (December 2012, New England). Lambeau Field is obviously no stranger to the cold (see: Ice Bowl, 1967 NFL Championship game, minus-13 degrees at kickoff).

Colin Kaepernick grew up a Packers fan, but playing at chilly Lambeau in January is not his ideal scenario.

"I don't think my dream was to play in freezing weather," Kaepernick said. "But to be in the playoffs and have this opportunity, yes, it's part of it."

Harbaugh's take on Kaepernick in the cold: "He'll be fine. He played in (college at) Reno, and they had cold-weather games there. Cold and windy."

Kaepernick, who led Nevada past host Boise State in 2010 when temperatures dropped into the 20s, said of Sunday's forecast: "You just have to block it out." He doesn't plan to wear a glove on his throwing hand.

  • Cornerback Carlos Rogers (right hamstring) did not practice. Harbaugh described the injury as "sore yesterday, better today, continue to see how the healing goes." The coach wants to see how Eric Wright, Tarell Brown, Perrish Cox and Darryl Morris compete this week for more playing time if Rogers can't go.

    Said Harbaugh: "We'll go out there today on the practice field, and that has a tendency to kind of scream to you, 'Play me. Count on me in this game,' or, 'Don't count on me.' So, I'm excited about it."

  • Ray McDonald and Patrick Willis said the AP's NFL defensive player of the year should be linebacker NaVorro Bowman. The winner will be revealed Feb. 1.

    "He has my vote," Willis said. "Coming back after the Arizona game, I said: 'Man, you're having the kind of year that linebackers want to have. I know you're most certainly having the kind of year that I would love to have.' "

  • Packers linebacker Clay Matthews (thumb) officially has been ruled out.

  • In what has become a Wednesday routine, center Jonathan Goodwin and defensive tackle Justin Smith did not practice and instead did individual conditioning. Smith, 34, and Goodwin, 35, are the 49ers' oldest players behind kicker Phil Dawson, 38.

  • Wideout Jon Baldwin (illness) did not practice. He has been inactive the past five games.