The question of how good the 49ers are versus how bad the Packers' offense might be plays into this matchup,but there is certainly a lot the Lions can do to help themselves regardless of how good San Francisco truly is.
When the Lions Are on Offense
These two teams could come at each other with similar game plans because both defenses are very good at rushing the passer. So they could both do what the Niner offense did to Green Bay's defense last week—kill each other with short, sharp passes to disrupt the pass rush.
For example, this play here: a short pass to Brandon Pettigrew. With a receiver on the outside, Pettigrew stays short and the coverage has already moved upfield to cover the deep threat.
With the coverage pulled upfield, Pettigrew has a lot of room to move.
In this set of downs, Stafford and the offense set up several short pass and run plays, then hit the defense long.
It's something the Niners can't do as easily because they lack Calvin Johnson and Matt Stafford's arm.
So the key for the offense is to work the short ball for a while—crossing routes to Brandon Pettigrew and screens to Kevin Smith and and make sure the 49ers can't tee off on Stafford.
While the Detroit offensive line isn't the worst in the league, it has issues. So the last thing they want is Navarro Bowman, Aldon Smith and Patrick Willis smearing the quarterback.
Here's another thing they have to watch out for.
Last week, the Niners would pull a linebacker for a defensive back at times to get a different style of look in their 3-4. On at least one occasion, the Niners brought one of these DBs up (in this case Parrish Cox) and—as you can see in the screen cap—lined him up over a receiver.
Aaron Rodgers must have thought Cox would drop back in coverage and checked him off pre-snap—but Cox blitzed and Rodgers got hammered.
The Lions have to be cognizant of this and need to keep someone short for a dump pass or a free blocker who can react to schemes like this.
When the Lions Are on Defense
The Lions had success moving around players on the defensive line and keeping the Rams guessing as to where pressure would be coming from.
This will continue to be the plan all season and should be just the thing to force Alex Smith into some mistakes. Now, Smith doesn't throw interceptions often, but the pressure will be so intense to where I am predicting one from him this weekend.
In the example here, the Lions are in a more standard formation—Nick Fairley and Ndamukong Suh inside—and the entire front four coming in to pressure quarterback Sam Bradford.
As you can see in the next picture, Nick Fairley gets right into the backfield—so quickly he stops in what looks like complete shock.
Then he resumes sacking the quarterback.
It won't come that easy—the Niners offensive line is much better than the Rams—but changing things up and getting quick pressure on the quarterback is the way to go.
A final brief note—look at how well the Lions have the rams receivers covered.
That has to be replicated this weekend or the 49ers will win. The Niners beat the Packers in the short and intermediate routes—and those are the areas the Lions have to be very careful about.
Even if the match seems tilted on paper, the Lions could very well take this game. With some early short set-up on offense, they can hit Johnson or Titus Young with a long pass later. And by moving the defense around, they can keep the Niners' offense guessing.
Do that and they give themselves a chance to win.