Gates was suspended for the first 4 games and I would hardly call 9 catches for 92 yards and 2 TD's in his first game back practically invisible.
To add to what Sschind said, not only was this the first game for Gates, but Woodhead and Keenan Allen are having great years. Rivers is a really good QB, but they have third stringers on their O-Line trying to protect him. Gordon is not having a great year, and I put a lot of that on the O-Line, no fullback and their TE's are not great blockers.
Defensively, they are small in the secondary, and have very little in the way of playmakers.
I fear for Rivers. He is not mobile, but is very tough. He most likely will get hit a lot in this game. Without Rivers, this is a 3 win team. With him, it is a .500 team.
All that being said, we are hurting in the secondary, receivers are thin and our own O-Line is weakened. Linebacking is getting thin and Raji is coming off an injury. Is Lacy still running with a taped ankle?
We are not without weakness, so although I think we win big, we cannot afford for anything to go wrong. If we get through this, then let's just get to the bye week and let some things heal for the stretch run. Nothing is certain, but unless something really bad happens, I believe we win big.
Disclaimer: I predict a Super Bowl Season every year in August, so take my statements with a grain of salt.