USA TODAY Sports
Lucie Safarova, No. 14 in the Power Ranking, hits a backhand during a match against Venus Williams in Cincinnati
15. Sara Errani: Once ranked as high as No. 5, Errani appears to be stuck in a rut. She lost her opening match against Muguruza in New Haven. She went ballistic over a bad call in a match in Cincinnati. Still, her ability to run down balls makes her a threat. It's also the reason she reached the semifinals in 2012.
14. Lucie Safarova: A remarkable run to the semifinals at Wimbledon was the highlight of her career. She took out Venus Williams in Cincinnati and lost a rather tight match, 7-5, 6-4 to Serena Williams in Montreal. Safarova, another lefty, has the shots. However, she lacks nerve on the big points.
13. Dominika Cibulkova: The runner-up at the Australian Open, Cibulkova has yet to recapture that career-making form. Bounced early in Cincinnati, Montreal and Stanford, Cibulkova arrived in New Haven this week hoping to get more time on the hard courts. However, she lost her opening match against Petkovic. She's lost five of her last six matches.
12. Flavia Pennetta: Since winning Indian Wells earlier this year, Pennetta has struggled. She lost to a qualifier in the first round in Montreal. Still, Pennetta is a solid hard-court player who reached the semifinals of the U.S. Open last year.
11. Victoria Azarenka: Her road back from injury has taken a detour out of the Top 10. The former No. 1 player and two-time Australian Open champion finds herself ranked No. 17. Still, she is among the best hard-court players. She reached the finals at the U.S. Open in 2012 and 2013. Both times she lost to Serena Williams.