Men to watch

Novak Djokovic: Rafael Nadal withdrew, and Roger Federer dropped the Sony from his schedule this year, making the path to a fourth title much easier for top-ranked Djokovic. He won his third consecutive Australian Open early this year and is 17-1 this season, the lone loss to Juan Martin del Potro in the semifinals at Indian Wells, Calif.

Andy Murray: The world No. 3 won this event in 2009, and he is familiar with the conditions and surroundings because his winter home is on Brickell Avenue. He spends extended periods of time training in Miami during the year.

Juan Martin del Potro: The tall Argentine is a crowd favorite in South Florida. His best finish was the 2009 semifinals. He is coming off an impressive week in Indian Wells, where he beat Murray and Djokovic en route to the final, where he lost to Nadal.

Tomas Berdych: He’s 6-5, has a big game and reached the Key Biscayne final in 2010. Don’t count him out.

Jo-Wilfried Tsonga: The Frenchman has never made it past the quarterfinals here, but he has the athleticism to do it, and he plays some of his best tennis on hard courts.

Women to watch

Serena Williams: The 31-year-old world No. 1 is going for title No. 6 in Key Biscayne, which would tie Andre Agassi for most ever. She has not played much since the Australian Open and has had some back issues, but she said she will be ready to play.

Victoria Azarenka: Remains to be seen whether she shows up. An ankle injury forced her to pull out of Indian Wells last week.

Maria Sharapova: Just when you wondered whether the one-time tennis “It” Girl could still be a threat to Williams, she goes and wins the Indian Wells title after not dropping a set. The win propelled her to No. 2 in the world rankings. She has reached four finals at Key Biscayne but never won.

Agnieszka Radwanska: The defending champion is gritty and proved last year she can win here.

Caroline Wozniacki: The former world No. 1 is one of the best retrievers in the game and can still make it hard for her opponents. She lost in the semifinals last year and is coming off a great week at Indian Wells, where she reached the final before losing to Sharapova.