Rodgers misses Cobb on a slant and Woodson picked it off. Rodgers didn't appear happy with Starks, who may have missed a block.
— Rob Demovsky (@RobDemovsky) August 1, 2012
I've been comfortable with James Starks as the running back of the near-future. He isn't a home-run threat, but he's a powerful runner who can keep defenses honest, and they can't teach just any player to be big and fast. While the Packers have been willing to let him pass block, it's never been seen as his strength, and he doesn't appear to be a natural at it.
Adam Czech paid some attention to pass blocking in his recent breakdown of the position, and reasonably decided to go with James Starks anyway. Apparently the coaches agree: it's better to play the running back that defenses' have to respect and then teach him how to pass block.
If they did want to go with a better pass blocker, it's not clear who's that would be. Maybe Alex Green or Brandon Saine are better, but I haven't seen enough from either player to know for sure. John Kuhn's probably a better blocker, but he's struggling with a bad knee and no defense has to give him any respect as an open field runner when he's healthy.
Of course, Ryan Grant is still a free agent, but he's never been known for his blocking either. The only free agent running back who came to mind was Clinton Portis, but that's not a Ted Thompson-like move (signing an unwanted veteran) and Portis sounds retired anyway (even if it's not official).
I don't have an answer to this question, going into the season with Starks as the starter sounds as good as any alternative, but I wouldn't be surprised to see a change if some problems pop-up during the preseason.