IMO the biggest question regarding the RBs is who can replace B Jackson as a blocking back on third down. Some have ignored his blocking ability on third downs, which helped Rodgers attain a fantastic passer rating when blitzed. So far IMO neither Green, Starks or Grant have matched B Jackson's ability to pick up the blitz. That could mean Kuhn will start the season as the third down back but he of course doesn't provide the threat Green or Starks do. The sooner one of them is able to do it, the better.