Where: Candlestick Park, San Francisco (grass)
Forecast: Mid-60s, 7 mph wind
When: Sunday, 4:05 p.m. ET (CBS)
Spread: San Francisco by 10
2012 records -- 49ers (8-3-1, NFC West: 2-1-1); Dolphins (5-7, AFC East: 1-2).
Past results: Two most recent meetings -- Dec. 14, 2008: Dolphins 14, 49ers 9; November 28, 2004: Dolphins 24, 49ers 17. Series record: Dolphins lead 6-5.
What matters: The 49ers should have their eye on the No. 2 seed in the NFC playoffs and a loss to the Dolphins -- especially at home -- would be a monumental step back. With four games left, there are two difficult road games -- at New England and Seattle -- so winning comfortably against the Dolphins would help ease the pressure headed into the final three. San Francisco also has to worry about the Seahawks making a late push for the NFC West title. Seattle is a game-and-a-half behind the 49ers with Arizona, Buffalo, San Francisco and the Rams left, with only the Bills on the road.
Who matters: QB Colin Kaepernick. All eyes continue to be on the second-year pro, who will make his fourth-straight start on Sunday. Kaepernick took a lot of heat for his play in the 49ers’ 16-13 OT loss to the Rams and in his last two starts, hasn’t matched the level of play he showed against the Bears on Monday Night Football on Nov. 19. With four games left in the regular season, the plan is for Kaepernick to get enough experience to where the 49ers have him in a place where they can win the Super Bowl. If it wasn’t, Alex Smith would still be the starter.
Key matchups: 49ers LB Aldon Smith and DE Justin Smith vs Miami rookie LT Jonathan Martin. Martin will be making his first career start at LT due to a season-ending injury to starting LT Jake Long. The injury occurred during Miami’s loss to New England last week, in which Martin was forced to make the shift during the game. With a week of practice, he should be better prepared, but it’s still a tall order for him to deal with Smith and Smith. Aldon Smith has 12 sacks in his last five games and is on pace to break the NFL single-season record.
Injuries of note: WR Mario Manningham (shouder) did not practice all week and is not expected to play. He is officially listed as doubtful for Sunday. LB Smith (shoulder) was limited in practice all week, but is probable, as are Patrick Willis (shoulder), Tarell Brown (hamstring), CB Chris Culliver (illness), LB Tavares Gooden (knee, elbow), RB Frank Gore (wrist), LG Mike Iupati (shoulder), CB Carlos Rogers (knee), K David Akers (pelvis), LB NaVorro Bowman (shoulder).
Inside stuff: RB LaMichael James is expected to make his NFL debut. Several teammates tweeted they were excited to see James play this weekend. If that's the case, expect him to be used in a role similar to what was expected of Kendall Hunter. James’ value is with the ball in space, meaning runs to the outside and potentiallyon read-option plays with Kaepernick. There is also the chance they let him return kicks or as a receiver in the slot.
Stat you should know: 48 and 10. San Francisco has 48 points this season on their first drive of the second half, which ranks No. 2 in the NFL. On defense, the team has allowed opposing teams to score just 10 points on the first second-half drive. Both stats speak to the effectiveness of the coaching staff’s halftime adjustments -- an unrivaled combination of stats in the NFL.
Looking ahead: Trips to New England and Seattle loom the next two weeks, neither of which is an easy place to play. After that, it’s the Cardinals at home -- the team Alex Smith was 18 of 19 against and earned NFC offensive player of the week honors.
Prediction: 49ers 24, Dolphins 12
Follow 49ers reporter Kyle Bonagura on Twitter @CBS49ers and @KyleBonagura.