she lost one match. it happens!
i can give serena the benefit of the doubt, because as a venus fan i watched her struggle to get back into form. was it painfull--absolutely! but, she didn't run and hide; she took her losses graciously (mostly--i mean even after sprem she was the height of grace) and now her game is coming back. kim came back too soon reinjured her wrist had to leave again, came back, reinjured something else, and the came back, lost the 4th round of two slams and then went on a tear culminating in her first slam title.
serena is not invincible and no one can really say for sure that she is not taking her tennis seriously. if she isn't, then she will soon learn that she can't take wins for granted anymore. but if her body won't/can't heal, all she can do is wait for it to catch up with her aspirations.