If we bring Bush in, I want him used as a wideout, preferably in the slot opposite of Moss. He won't hold up, or be very effective as a RB.
Moss, Armstrong on one side, Kelly and Bush on the other side.
When Kelly goes down, plug in Fred Davis in his spot in the 4-WR package.
If Rex is our QB, just load up the field with receivers and let him do his thing 50 yards down the field.