Serena Williams has angrily rejected claims that she and sister Venus are a declining force in tennis.
The sisters ended last year without a Grand Slam title for the first time since 1998.
But Serena denied their challenge was fading, saying: "That's not fair - I'm tired of not saying anything.
"We've been practising hard. We've had serious injuries. I've had surgery and after, I got to the Wimbledon final. I don't know many who have done that."
While Serena is through to the Australian Open semi-finals, Venus went out in the fourth round, meaning she has not gone further than the last eight in her last five Grand Slam appearances.
But Serena added: "Venus had a severe strain in her stomach. I actually had the same injury, but I didn't tear it the way she did.
"If I would have torn it, I wouldn't have been here.
"She played a player (Alicia Molik) that just played out of her mind and Venus made some errors that she probably shouldn't have made."
Serena also said people tended to forget the impact the 2003 murder of sister Yetunde Price had had on the family.
"To top it off, we have a very, very, very, very, very close family" Serena continued.
"To be in some situation that we've been placed in in the past little over a year, it's not easy to come out and just perform at your best when you realize there are so many things that are so important.
"So, no, we're not declining. We're here. I don't have to win this tournament to prove anything. I know that I'm out here and I know that I'm one of the best players out here."