Should i drop Mike Tolbert and pick up Donald Brown?

I need another RB for this week, right now i have Tolbert starting and he has been efficient but he'll be sharing carries with Ryan Mathews and Sproles, while Donald Brown will be starting. I dont wanna drop Tolbert but i have no one else to drop. My bench is: Kyle Orton (bye), Brandon Lloyd(bye), Malcom Floyd(injured), Sims-Walker(bye), Ryan Torain(bye) and Reggie Bush(injured). Drop Tolbert???