I'd most likely sit Portis, he's going up against the #1 run defense in the NFL. Edge and Lynch are facing cake walk defenses this week in Atlanta and the Giants, whom Portis humiliated last week.
You have to start Welker, coming off a very sup par performace and going up against Miami, NE is going to light it up.
I say that with a heavy heart as i'm facing Brady and Moss in the championship this weekend...Good Luck