Roger Federer's struggles continue. And the once-impeccable and unflappable champion is showing signs of cracking.Trailing in the third set to Novak Djokovic in the semifinals of the Sony Ericsson Open, the 13-time Grand Slam champion unleashed his frustration on his racquet after missing a surefire winner into the net. The mangled mess of a racquet did not change the momentum of the match, as Djokovic cruised to a 3-6, 6-2, 6-3 victory.
Later in the third set, the usually reserved Swiss -- we expect this from Andy Roddick or Fernando Gonzalez or Lleyton Hewitt, but not Federer -- flipped his empty water bottles behind his seat in disgust. He even forgot to shake the umpire's hand after the match. Totally out of character and a window into Federer's fragile state.
Video of Federer's tantrum after the jump.




