My biggest fear is the same as it has been for the last few years, defensive backs. Obviously, offensive line and quarterbacks are very suspect, but I feel that with Harbaugh's play calling, we will be much improved on offense. I think we could have won 2 or 3 more games last year with better play calling and coaching decisions.
Whenever decent passing teams decide to really start passing on us, it seems we are unable to stop them. Some of that is/was probably scheme, but we have not had a really good cover corner/safety. There always seems to be way to much cushion. I hope the free agents and young players can turn things around, but I kind of doubt it.
Let me know if you disagree, and why you chose what you chose.