If the 49ers are to win their next game against these Lions however, the 49ers offensive and defensive lines are going to have to dominate play in the trenches.
This will be each line's biggest test of the season, and will tell a lot about how good this 49ers team really is.
From watching last Monday Night Football's game against the Chicago Bears, we saw a Lions defensive line anchored by DT Ndamukong Suh teeing off on the pass-rush and affecting nearly every play in the second half.
This will be the biggest test for an emerging offensive line in San Francisco.
Anchored by LT Joe Staley, this line will face its first game of the year on turf and a speed rush with a strong push from Suh and company in the middle.
Add to Suh his 320-pound starting DT companion Corey Williams, and then first-round DT draft pick Nick Fairley, and the interior of the 49ers offensive line starting with G Mike Iupati are going to face fresh bull-rushers all game long.
Add to that veteran DE Kyle Vanden Bosch, who is Detroit's version of Justin Smith, and you have a formidable and deep defensive line that is going to be motoring every play for 60 minutes.
If the 49ers can keep possession of the ball by leveraging a mismatch with whomever lines up against Vernon Davis, then the 49ers could wear this defense down.
Look for Harbaugh's game plan to continue to have QB Alex Smith throw the ball early to give the line help in facing a defensive line that is far more dominant on paper.
With proper game management and strategy, this young 49ers offensive line can be up to the task.
The Lions' offensive line lacks the star power of the defensive line, although their job is much easier.
Anchored by veterans Rob Sims and Jeff Backus, it doesn't take much of a running lane for RB Jahvid Best to make a dash through the secondary.
It's going to take a monster effort to shut down this speedster, and if anyone can do it, it's San Francisco's speedy linebacker core.
So long as Justin Smith and company can dominate the line play and plug up the gaps, the 49ers linebackers are better set than most teams in the NFL to shut down the Lions' running attack.
Which leads us to the Lions' biggest threat and the 49ers' biggest weakness on defense, which is the passing game.
Look for Carlos Rogers to have a breakout game against WR Calvin Johnson if the 49ers are able to get a good pass-rush on Lions QB Matthew Stafford.
It's going to be up to Ahmad Brooks and Aldon Smith to play their best games of the year thus far to get the kind of pressure necessary.
This won't be easy considering the effort it's going to take to shut down the run game from the defensive line, and the fact that the Lions get the ball out quick and complete a lot of quick passes.
If the 49ers remain patient, and the rush gets to Stafford when the Lions do take a shot down field, then the offensive line's job for the Lions will be a lot harder than they're used to and it could get pretty ugly for the Lions for what will turn into a marathon of a game.
Forget about Josh Morgan's injury or any other thing that might have to do with this game.
This game is coming down to how well the offensive line of the 49ers fends off a furious Detroit pass-rush, and how well the 49ers' defensive line gets pressure into the backfield so the 49ers linebackers can open up and make plays.
That's it. Just those two things. And for anyone who loves smashmouth football, you're going to get it in this game on Sunday.