Agreed. But it's more than that. In no particular order, here are some of the Sox problems.
Effectively only 8 batters in the lineup while other teams seem to always have 9. Starting pitching is still questionable. Beckett apears to have regained his stuff (at least in the last two outings). Wake will be Wake over all. Good for .500 ball and "eating innings". Dice K is what he is and will in all likelihood underachieve this season and have a drop-off from 18-2.
Penny, while being a pleasant surprise so far, is actually a 5th starter in 5th starter's clothing. May not be with the Sox too much longer. Lester shows glimpses of being the 1A of last year but remains a question. Shmoltz looms but what can we actually expect from him? Does anyone expect him to be the pitcher he has been in the past? Buckholtz/Bowden may make appearances but despite being dominant in AAA, neither is a proven commodity in the bigs.
Lack of a MLB shortstop. Defense at 6 has been dismal. Lowrey will be back in July. Let's hope he regains strength in his wrist and reacquires his timing at the plate. And soon.
Outfield depth is a problem. As much as I like Rocco, it appears he will not be able to play well enough on a consistent basis to be a factor. Kotsay is due back next week, which is good. He plays OF and 1st base. But what kind of bat does he really bring? Drew is slumping significantly. How long will this last? I like Ellsbury. But he needs to get on base more to really have an impact offensively.
This team was, presumably, built to win a pennant and possibly the series this year.
The problems I have listed need to be addressed soon for the Sox to be able to compete for a spot in the post season.