Use him on the obvious passing downs, or on option plays. His strength is turning upfield when he has some space. He is below average running between the tackles.
Ropati looks like Tarzan and plays like Jane. He is built like a brick and has a low center of gravity, so he has all of the physical tools to be an awesome runner between the tackles. His issue is field vision and a lack of patience for holes to open up. I stopped counting the times that he ran straight into the back of an offensive lineman, or straight into a DL or LB.