Where: Candlestick Park, San Francisco (grass, outdoors)
When: Sunday, 4:25 p.m. ET (FOX)
Spread: 49ers by 16.5
Records: 49ers (10-4-1, NFC West 2-2-1); Cardinals (4-10, NFC West 2-3)
Past results: Two most recent meetings -- Oct. 29, 2011: 49ers 24, Cardinals 3; Dec. 11, 2011: Cardinals 21, 49ers 19. Series record: 49ers 25-17.
What matters: It’s pretty simple: If the 49ers win, they’re the NFC West champions and will host their first playoff game. Whether that will be in the wild card or divisional round depends on the Minnesota-Green Bay game. If Green Bay wins, the Packers get the No. 2 seed. If Minnesota wins, it goes to the 49ers. If San Francisco loses to Arizona and Seattle beats St. Louis, the Seahawks would be the division champion.
Who matters: DE Ricky Jean Francois. Justin Smith’s replacement on the defensive line has been a focal point of criticism by default. Since Smith left the New England game two weeks ago, the 49ers' defense has gone into the gutter, and it’s been easy to point to change as the primary reason. It’s impossible to say just how much the loss has been a factor, but all eyes will be on Francois, regardless. Recently promoted Tony Jerod-Eddie will also be in the rotation at defensive end.
Key matchups: Arizona RG Adam Snyder vs. 49ers DT Isaac Sopoaga. Snyder signed with the Cardinals in free agency in the offseason after spending seven seasons with the 49ers. It will be interesting to see how Sopoaga fares against his old teammate, playing alongside Francois. ... 49ers CBs vs. Cardinals WR Larry Fitzgerald. Just who spends most the game on Fitzgerald remains to be seen, Tarell Brown figures to see get a lot of time, as does Carlos Rogers.
Injuries of note: DL Justin Smith will be out with a partially torn triceps ligament. TE Vernon Davis was officially listed as questionable as he needs to pass the contact test before being cleared to play. DL Will Tukuafu (neck) is also listed as questionable and will likely be sidelined.
Inside stuff: RB LaMichael James has made a significant impact in the return game since his debut against Miami three weeks ago. Considering he has averaged 29.5 yards per kickoff return, the math says that taking a knee is rarely the logical choice for James.
Connections: 49ers LS Brian Jennings and Cardinals TE Todd Heap were teammates at Arizona State (1998-99); 49ers DT Ricky Jean Francois and Cardinals WR Early Doucet were teammates at LSU (2006-07); 49ers P Andy Lee and Cardinals WR Larry Fitzgerald were teammates at Pittsburgh (2002); 49ers RB Frank Gore and Cardinals DE Calais Campbell were teammates at Miami (2002); 49ers coach Jim Harbaugh was a QB for Baltimore in 1998 when Cardinals coach Ken Whisenhunt was the team's TE coach; 49ers secondary coach Ed Donatell was a graduate assistant for the University of Washington when Cardinals defensive coordinator Ray Horton was a CB for the team (1981-82).
Record watch: LB Aldon Smith needs 3.5 sacks to break Michael Strahan’s single-season sack record.
Stat you should know: WR Michael Crabtree needs 67 yards to reach the 1,000-yard receiving mark for the season.
Looking ahead: The playoffs start next week. Whether the 49ers play or have a bye remains to be seen.
Prediction: 49ers 31, Cardinals 12
Follow 49ers reporter Kyle Bonagura on Twitter @CBS49ers and @KyleBonagura.