Sharapova had 'shoulder injury' or she just wasn't good enough?
I see the 'shoulder injury' becoming just the main excuse Maria gives for her losses.
Evident from her early round interviews, wasn't she already much happier since she was improving so much? Case in point, her match against Bremond. She appeared to be serving and hitting really well. Yet, when she fails to advance, she attributes a number of reasons: shoulder injury (which is most common), nothing worked for her that day and her failure to take advantage of opportunities. On the other hand, players probably raised their game to another level when playing Sharapova. Therefore, may be she had a bad day and couldn't try to keep with the level. In other words, she couldn't raise her game when she needed to. Time and again, she has lost quite easily to the Williams sisters in Grand Slams. After all, she's probably not as mentally tough as one might think.