yah this is a hard one, i would go with Portis this week, more touches are in hand for Portis, Doesn't look good for Greene this week another tough matchup and LT is a better Running back vs tough Defense's like the Patriots.
QB:Stafford, Big Ben
RB: AP,Run DMC,Felix Jones,Ben Tate,
WR: DeSean Jackson,Percy Harvin,Ocho,Burleson
TE: Kellen Winslow
K: Nick Folk