Start Philip Rivers
This should be an every week thing, at least until he cools off and Ryan Mathews returns. As it stands, the San Diego Chargers still have one of the league's best offense and have no way of getting into the end zone without getting Rivers' fantasy owners some points with a passing TD.
Sit Donald Brown
If there was ever a week to pick up Donald Brown and start him in hopes that he'd replace Ryan Mathews production, this isn't it. Brown will be going up against the league's best run defense with a pretty terrible offensive line in front of him. Expect negative yards and zero touchdowns from Brown.
Start Keenan Allen
I've been saying it all week. Rex Ryan will force Rivers to beat him with medium-depth sideline throws. There is nobody on this team better at running medium-depth routes to the sidelines than Keenan Allen, and nobody that Rivers trusts more to make that throw to (because he'll come back to the ball and beat any CB there). He'll get a lot of passes thrown his way on Sunday and will have a ton of yards.
Sit Eric Decker
The Chargers have basically shut down every #1 WR they have faced so far this year (thank you, based Brandon Flowers), and Decker is reeling with leg problems. If he plays, he probably won't do much.
Start the Chargers defense
Michael Vick turns the ball over a lot and still doesn't turn it over as much as Geno Smith. Smith threw 21 INTs in 16 games last year and is on pace to throw 20 more this year. That's more than a pick per game, and he fumbles plenty too. Turnovers mean points in fantasy, so get them while you can.