Maria Sharapova returns to competitive action at the Western and Southern Open in Cincinnati this week, after bypassing the Rogers Cup due to injury. Sharapova, the 2011 champion, cited a "right leg strain" as her reason for skipping the Toronto event, but she is seeded second at the WTA Premier hard-court event in Ohio - the penultimate tournament before the US Open gets underway. The Russian's two previous appearances were at the French Open (fourth round) and Wimbledon (semi-finals), with her last non-major tournament showing seeing her lift the Rome title in May. The world number two's inclusion in the draw means only two of the WTA's top 30 are missing - with world number 12 Ekaterina Makarova absent, having withdrawn from the doubles event in Canada due to an unspecified ailment. Svetlana Kuznetsova is the other in that bracket not playing. Sharapova will take on either Barbora Strycova or Varvara Lepchenko first up after a bye, with the latter the beneficiary into the main draw at Makarova's expense. Belinda Bencic will have to back up her breakout week at the Rogers Cup with a tough first-up clash with 11th seed Angelique Kerber. It is one of several anticipated clashes for the seeds who do not have byes, with number 10 Carla Suarez Navarro facing American Sloane Stephens - and 12th seed Timea Bacsinszky drawing another talented local in Madison Keys. Serena Williams is the top seed, and will look to bounce back from just her second loss of the 2015 season in the Toronto semi-finals to Bencic. Williams is the defending champion, after her first title at the event in six attempts 12 months ago. Elder sister Venus Williams could face Serena in the quarter-finals, but she would first have to overcome Zarina Diyas and then 2014 finalist Ana Ivanovic to have any chance of a showdown. Venus would also need a turnaround in fortunes, having lost both her matches since her fourth-round loss to Serena at Wimbledon. In other potential quarter-final match-ups, Czech left-handers Petra Kvitova and Lucie Safarova are on a collision course, while Caroline Wozniacki and Simona Halep are in the same section - although Wozniacki is likely to play nemesis Victoria Azarenka in the second round. Azarenka, the 2013 champion in Ohio, has won her past four matches against the Dane, all in straight sets. In Sharapova's quarter is Karolina Pliskova, enjoying the spoils of an eighth seeding at a Premier event for the first time - which sees her get the bye before a potential second-round clash with one-time US Open winner Samantha Stosur.