Serena Williams is the overwhelming favorite to win the 2013 U.S. Open.
The debate is over who her top challenger is.
But which player has a better chance?
They are the only women, other than Williams, to win a Grand Slam title in the past two years. Unfortunately, they have a combined 4-26 record against her. Yet they have as good a shot as any of keeping Williams from winning a fifth U.S. Open championship.
Although Sharapova is ranked No. 2, recently Azarenka has given Williams the tougher challenge. Azarenka defeated Williams at the Qatar Open in Doha in February. It's one of only three losses Williams has suffered this year. Sharapova, despite putting up a fight at the French Open, has lost 13 straight to Williams.
Both women are nursing injuries sustained during their short run at Wimbledon.
Azarenka pulled out before her second-round match after suffering a knee injury in the first round. Sharapova injured her hip during a second-round loss. She later withdrew from Stanford, and Sunday, she announced she was withdrawing from Toronto, as WTA Tennis reported.
Azarenka returns to the courts this week at the Southern California Open. She said to Jeff Sanders of the San Diego Union-Tribune that she was confident her knee would be ready.
Sharapova recently hired American tennis great Jimmy Connors as her new coach. Connors replaces Thomas Hogstedt, who retooled Sharapova's game after her shoulder surgery. But no coaching change can dramatically improve Sharapova's game over a matter of weeks.
With Azarenka and Sharapova ailing and both so close in accomplishments, the difference between the two comes down to belief.
Which one truly believes she can beat Williams?
That edge goes to Azarenka.
Azarenka squandered a 5-3 lead in the final set of the 2012 U.S. Open. But her performance proved she could go toe-to-toe with Williams. She backed it up with the win in Doha.
Sharapova doesn't seem capable of mounting a "comeback" against Williams. She's not even able to hold onto a lead. She was up 6-4, 3-2, to Williams in Miami, only to relinquish the final 10 games. She lost 6-4, 3-6, 0-6.
Perhaps, hiring Connors will turn out to be a "game-changing" move against Williams. It's unlikely. The last two outings against Williams, Sharapova played her best. It just wasn't good enough.
Azarenka, when healthy, not only believes she can beat Williams, but welcomes the challenge. She walks with a bit more swagger against Williams. When she loses to Williams, Azarenka looks disappointed. Sharapova looks demoralized.
Deep down, Azarenka knows that her defeat against Williams at the U.S. Open was as much about her collapse as it was about Williams' resilience.
When it comes to challenging Williams, Azarenka stands a better chance than Sharapova.
Williams knows this. Tennis fans know it. Most importantly, Azarenka knows it.