This is a game where both teams are seen as true Super Bowl title contenders, but the 49ers have an edge because they are at home and coming off a bye week. Plus, they took care of the Packers in Week 1 at Lambeau Field.
"Our players like (being underdogs)," McCarthy said Sunday, according to Comcast SportsNet Bay Area. "I think they respond better when they're disrespected, and I'm sure that we'll get some of that this week, too, because we weren't successful in the first week. So I think it brings a little more energy."
The Packers really won't be too disrespected. Much of the national media, including yours truly, still sees them as potential champions. But this certainly is a different setup from a year ago when the Packers were the No. 1 seed, expected to cruise past the New York Giants. This is a toss-up game.
There still are questions if the Packers' defensive front seven is deep enough, but ultimately we see this squad as one that is peaking at the right time. Green Bay's receivers are as healthy as they've been all season. DeJuan Harris has added a big dimension to the running game.
Follow Gregg Rosenthal on Twitter @greggrosenthal.