While in many aspects the game figures to be a snoozer (the folks in Vegas certainly think so, as the Niners are 16.5-point favorites, their highest line since 1998), it will be important for the home team in a few respects.
For starters, the 49ers still have a chance to grab the second seed in the NFC and the first-round bye and guaranteed home-field advantage in the divisional round that comes with it. All they have to do is beat the terrible Cardinals and get some help from the Minnesota Vikings, who host the Green Bay Packers.
A 49ers win and a Packers loss means a week's vacation for everybody, and if any team could use the time to rest and recuperate, it's a banged-up 49ers squad. While hoping for a loss from a red-hot Packers team seems like wishful thinking, at least the game is ultra-important for the Vikings, who need to win to make the playoffs, so there's no doubt they'll be giving their best.
Also, Adrian Peterson is still within range of Eric Dickerson's single-season rushing mark of 2,105 yards, so the Vikings will be primed for that one.
Even ignoring the result of the NFC North clash, the game vs. the Cardinals will be important for the 49ers just to capture the NFC West for a second consecutive year.
If they somehow get shockingly upset by Arizona, a Seattle win at home against the St. Louis Rams will relegate the 49ers to Wild Card status, and they'll be on the road next week, taking on the winner of the Dallas-Washington tilt which will settle the NFC East.
Finally, forgetting all the practical implications, it will be important for the 49ers to get a win just to build some momentum going into the postseason. They got waxed by 29 points (and it wasn't that close) and suffered numerous injuries to key players. It's hard to think of another team going into the playoffs with more ominous, negative energy.
Still, it could be worse. They could be the Cardinals.
Arizona started brightly, winning their first four games including a stunner at New England, but have been miserable ever since starting QB Kevin Kolb got injured, dropping 10 of their last 11 games, including a 24-3 loss at home to the Niners on Oct. 29 on Monday Night Football.
Alex Smith completed 18-of-19 passes for 232 yards and three touchdowns in that game and was named NFC Offensive Player of the Week for his efforts. He suffered a concussion against the Rams the next week and has been benched ever since in favor of Colin Kaepernick, who has been stellar in most of his starts but quite mediocre in games within the division.
Brian Hoyer will be making the first start of his career for Arizona, their fourth different starting quarterback of the season. He'll be looking to break a streak of 12 NFC West visiting quarterbacks who have left Candlestick Park without a win, as the 49ers have gone 11-0-1 in their last dozen home games in the division.