Kim Clijsters was scheduled to meet the winner in the second round on Wednesday and the number two seed is likely to be relieved after saying on Monday she would not have been happy to beat her sister.
She said the situation made her realise what Serena and Venus Williams must experience when they had to play each other in tournaments.
The Williams sisters have met in six grand slam finals, with younger sister Serena winning five of them.
"Now
"I am in the position of Venus who always said that she wanted Serena to win because she is the little sister. Now I understand what Venus said."
"If it occurs, the situation will be difficult. I don't know what to expect, but I am sure I will not be happy to win. Just like the Williams when they played finals of grand slams, the winner never seeming happier than the loser," she added.
However the Clijsters sisters played together later on Tuesday in a first-round doubles match against Tunisia's Selima Sfar and Caroline Vis of the Netherlands, trouncing their opponents 6-1, 6-0.
