The Olympic silver medallist and bronze medallist Maria Sharapova and Victoria Azarenka headline the women's field at the WTA Rogers Cup in Montreal this week.
Gold medallist Serena Williams is not in the draw this week which should give her rivals a chance to pocket some hardware and confidence before the US Open which begins in 3 weeks.
Azarenka has reached the semi finals here thrice in her career and will be aiming for her first title since March. She won 4 titles in the beginning of the year.
Sharapova is just 100 points behind Azarenka in the race for the top spot and could overtake her this week.
Wimbledon finalist and world no. 3 Agnieszka Radwanska also has a chance to ascend to No.1 after Montréal.
"Grass courts are totally different than hardcourts," Radwanska commented. "It's going to be a bit tough to adjust, especially the first match. But I've had good results on hardcourts this year. So I just hope I can continue that."
Also in the field are former champions Caroline Wozniacki and Ana Ivanovic.