Keys to the game: 49ers/Lions
Pound the rock with Frank Gore and Kendall Hunter
Gore has a history of running wild against the Lions, and he set the tone of San Francisco's thrilling 25-19 victory at Detroit last year while rushing for a season-high 141 yards on just 15 carries, which included breakaway runs of 55 and 47 yards. Since Gore entered the league in 2005, he averages more yards rushing against the Lions than any other NFL back, and that has been a formula for a San Francisco victory in each of those games. Gore's grinding on the ground helped the Niners control the tempo of last year's game, when San Francisco's passing game produced only 111 net yards. The Niners did the same thing last week against the Packers with a nice mix of Gore and Hunter; the same pattern needs to be established here.
Put the heat on Matthew Stafford
Detroit's record-setting quarterback did not handle well the relentless pressure the 49ers put on him in last year's game, and by the end of it he was waving the white flag while tossing weak throws into the turf on Detroit's final drive when the Lions still had a shot at victory. Stafford is a rhythm quarterback who gets rid of the ball quickly and can be extremely productive when he finds his comfort zone. But he can also be rattled into mistakes and quick-trigger incompletions, as the 49ers vividly displayed last year. After last year's game, you can be sure Stafford is wary of this rematch. The Niners have to stay in his face all day.
Niners interior offensive line vs. Detroit interior defensive line
This one is going to be a true battle in the trenches, and Niners' center Jonathan Goodwin and guards Mike Iupati and Alex Boone will face one of their top challenges of the season with Detroit's trio of big and nasty defensive tackles. Detroit DTs Ndamukong Suh, Corey Williams and Nick Fairley each bring a load, and neutralizing them in the middle will be a must for San Francisco's offense to hum along smoothly like it did last week at Green Bay. Boone had an auspicious starting debut at right guard against the Packers last week, and he'll find himself in some individual matchups with Suh, who the 49ers practically took out of the game last year. Suh, Williams and Fairley each had quarterback sacks in Week 1 against the Rams, so the 49ers will have to do a job on this threesome in both run blocking and pass protection.
Attack Lions' banged-up secondary
The Lions are dealing with some injury issues in their defensive secondary, and to exacerbate the problem for Detroit, their secondary isn't very good even when it's healthy. The Lions were exposed often through the air last season, but that didn't necessarily happen when the 49ers came to town in Week 6. Alex Smith completed 17 of 32 passes for just 125 yards, and while his winning TD pass was one of the game's biggest plays, the 49ers didn't emerge with victory because of what they did with their passing game. With Detroit so vulnerable through the air, and San Francisco featuring considerably more passing/receiving firepower than last year, the Niners need to strike through the air consistently like they did last week, when they had exceptional offensive balance against the Packers.
Limit Megatron's big plays
You can't really stop Calvin Johnson. But you can hope to contain him. The 49ers certainly have a plan for Detroit's awesome All-Pro wide receiver, and they must limit him from taking over the game, something of which Johnson certainly is capable. The 49ers will attempt to contain Johnson within their defensive structure – which means they won't change their standard game plan just to stop one player – so there will be occasions when Megatron will find himself in single coverage with a San Francisco cornerback. The Niners have to make sure those matchups don't turn into a collection of big plays for the Lions.
Keep the Lions off Alex Smith's back
The Lions will look to disrupt San Francisco's offensive rhythm by pressuring Alex Smith, and they have the front seven on defense to do it. Smith was sacked 44 times last season, more than any other NFL quarterback, and he was under siege last week when the Packers sacked him four times and hit him on several other occasions. Smith continues to emerge as a passing threat and he protects the football in exemplary fashion, but he can't have Detroit defenders breathing down his neck all day if the 49ers expect him to make plays and direct their offense efficiently.
Keep close on the TEs
Detroit has a dangerous and productive trio of targets for Stafford at tight end in Brandon Pettigrew, Tony Scheffler and Will Heller. That trio had 12 receptions for 126 yards in last week's victory against St. Louis, and Pettigrew and Scheffler were the targets of a combined 18 passes from Stafford. Detroit likes to throw to its tight ends and use them as a weapon as the Lions spread the field with Johnson, Nate Burleson and other wideouts. This creates matchup problems galore for any defense, and those Detroit tight ends will find themselves being covered several times by San Francisco linebackers, who must stay close in those situations. Sometimes even being close isn't enough, as Pettigrew showed last year when he made an athletic grab for a touchdown reception even with 49ers linebacker Patrick Willis draped all over him with fantastic coverage.