While the men are in Europe and Australia for the Davis Cup quarterfinals, the WTA is staging events in Mexico and South Carolina -- where the clay season officially begins. Once the Family Circle Cup, the Volvo Car Open has become the largest women's-only tournament in North America.

Here's what we're watching for:

Volvo Car Open, Charleston, South Carolina, clay

Madison Keys is a top seed for the second time in her career at this week's Volvo Car Open. It will be her third tournament of the year following time off to recover from wrist surgery. Jayne Kamin-Oncea/USA TODAY Sports

Top seeds: 1. Madison Keys, 2. Johanna Konta (WD), 3. Venus Williams, 4. Elena Vesnina, 5. Caroline Wozniacki, 6. Samantha Stosur, 7. Kiki Bertens, 8. Anastasija Sevastova

Storylines: Many of the best players in 2017 will be in action, although Konta, fresh off the biggest title of her career in Miami, withdrew Monday because of a shoulder injury. Indian Wells champion Vesnina and 36-year-old Williams, who lost to Konta in the Miami semifinals, are playing. Keys, who missed the beginning of the year following wrist surgery, is a top seed for the second time in her career. Keys won three of five matches in her comebacks at Indian Wells and Miami. There are five former champions here: Williams, Wozniacki, Stosur, Jelena Jankovic and Andrea Petkovic.

Of note: Also in the draw is Lucie Safarova, who reached the quarterfinals in Miami. She's won 13 of her past 17 matches, was a Charleston finalist in 2012 and could meet Williams in the third round.

Abierto GNP Seguros, Monterrey, Mexico, hard

Angelique Kerber is ranked No. 1 in the world but hasn't reached a final in her seven starts this year. AP Photo/Mario Houben

Top seeds: 1. Angelique Kerber, 2. Anastasia Pavlyuchenkova, 3. Caroline Garcia, 4. Carla Suarez Navarro, 5. Timea Babos, 6. Ekaterina Makarova, 7. Alize Cornet, 8. Christina McHale

Storylines: The No. 1-ranked Kerber is playing her eighth event of the young season and is still looking for her first title. She's 12-7 but started to regain some momentum before losing to Venus Williams in Miami's quarterfinals. Pavlyuchenkova loves this tournament, having won it three times in four years from 2010 to '13. She, however, was stunned by Bethanie Mattek-Sands in the third round at Miami.

Of note: Kerber's first opponent is Francesca Schiavone, the 2010 French Open champion. Eugenie Bouchard is also in the field; she could play Suarez-Navarro in the second round. Catherine "CiCi" Bellis is in her last week as a 17-year-old.