The Lions' Ndamukong Suh gets most of the attention after his 10-sack rookie season. A few scouting types I've spoken with said they thought Detroit's other defensive tackle, Corey Williams, has played at least as well and even better. Williams will line up over 49ers left guard Mike Iupati for what should be a fierce battle. Williams did suffer an foot injury in practice this week, but he's starting.
The 49ers know they need to minimize crowd noise by starting the game well. Otherwise, noise threatens to be a big problem for tackles Joe Staley and Anthony Davis, who face tough enough matchups anyway.
There's little question the 49ers will try to emphasize the run. They'll want to make the Lions pay for lining up their defensive ends wider than most teams line them up. They should like their matchups in that regard, but Alex Smith and the passing game will need to function well enough over the course of the game to keep the Lions' defense honest. Smith has appeared decisive and comfortable lately, getting rid of the ball quickly. That must continue.
Chris Culliver and Shawntae Spencer are both active at cornerback for the 49ers. I would expect Culliver, the rookie third-round pick, to serve as the first corner off the bench in nickel situations. Veteran Carlos Rogers moves inside in those situations, potentially leaving Culliver outside against Calvin Johnson. The 49ers will obviously need to help out with a safety in those situations.
The Lions have been effective at times throwing underneath passes to Jahvid Best in particular. The 49ers' Aldon Smith isn't on the field for all situations, but the rookie outside linebacker does possess arms long enough to contest some of those throws. He had a key tipped pass against Seattle in the fourth quarter of the opener. Something to keep in mind.
The Lions rank 20th in punt-return defense and 28th in kick-return defense, defined by average return lengths. That makes the 49ers' Ted Ginn Jr. a player to watch. Few things sap the life from a crowd more than a touchdown return from the visiting team.
Kevin Seifert and I are getting settled in here before kickoff. I'm seeing quite a few fans wearing 49ers jerseys ringing the visitor's sideline and sprinkled throughout the still mostly empty blue seats. The first two fans I saw outside the stadium Sunday morning were wearing Patrick Willis jerseys.