I agree with the other poster. Flex your TE (either of those guys can have monster games and both are favorite targets of their respective QBs)
For RBs, I'm worried about Gore's ankle even though he is normally a must start. Johnson is up against the worst run defense in the league but hasn't managed to do much this season. Murray is a madman and Jacobs is going up against a brutal D. If Gore is REALLY looking healthy, then Gore and Murray, else Johnson and Murray.
Additional info...If you end up activating Bradshaw or thinking about Jacobs, remember that the 49ers D has NOT given up a rushing touchdown ALL SEASON, they have only allowed 1 run more than 20 yards (24 actually) so I would avoid them.
Lineup (starters in Bold)
QB - RG3, Romo
RB - McCoy, MJD,AP, MJD
WR - Nelson, Austin, T.Smith, Wallace
TE - Graham, Bennett
DST - Lions
K - Tucker