Serena has not had the best week at Wimbledon. She has been snappy with the media and her withdrawal from the doubles game with her sister, Venus, gives us a pretty good clue as to why she has been so off her game.

During the warm up, Serena was off-balance, uncoordinated , and looked like she was really struggling to even hit the ball over the net. This is not a normal sight for the usually powerful Williams sister. She fumbled trying to retrieve the ball from the ground numerous times in both the warm up and the actual match and eventually broke down in tears.

Shriver [ESPN commentator] questioned whether Serena had taken something. “This is not an illness,” Shriver said. “It’s almost like she has taken something that makes her feel dizzy, disoriented, and she cannot reach up and strike the ball.”

This is a pretty wild accusation, Pam, have you ever tried to play championship tennis with a fever? Or, for that matter, make a cup of tea with a sever viral infection?

Perhaps we are being lenient but either way, this is certainly out of the ordinary for the tennis powerhouse.

Find more clips of Serena warming up as well as more info check out Business Insider.