Definitely drop Royster for Luck. Then just sit on Luck and decide if you want to keep him as the season progresses.
Seems a pretty safe plan to me. Between a Mike Shanahan offense, Alfred Morris, and Roy Helu, you shouldn't be expecting too much from Royster.
If you wouldn't mind: viewtopic.php?t=520074
QB: Matt Ryan
RB: Ray Rice, DeAngelo Williams, Mark Ingram
WR: Greg Jennings, Marques Colston, Denarius Moore
TE: Vernon Davis
K: Dan Bailey
Bench: A. Luck, F. Jackson, J. Rodgers, B. Jacobs, D. Amendola, N. Burleson, K. Wright, B. Celek