World number one Serena Williams has said that it is "not guaranteed" that she will come away from Wimbledon holding all four Grand Slam titles.
The American is the top seed in the women's draw at SW19, but has made it past the fourth round at the grass-court tournament just once in the last four years.
The five-time Wimbledon champion told reporters: "I don't think about it, but every time I come into the press area you guys talk about it. It's definitely historic, but it's also six matches away and not guaranteed. I'm just going to enjoy holding three titles right now."
Williams beat Margarita Gasparyan 6-4 6-1 in her first-round match yesterday.
