Serena Williams unsure over fitness

Serena Williams has revealed that she is unsure whether she will be fit enough to defend her Italian Open title.

A thigh injury recently forced the world number one to pull out of her quarter-final encounter with Petra Kvitova at the Madrid Open.

"I'm taking it a day at a time, we'll see as the week goes on," the 17-time Grand Slam champion is quoted as saying by BBC Sport.

"I'll see how I feel tomorrow (Tuesday). I hit some balls today a little bit so I'm going to see later tonight how it feels."

Williams, who has a bye in the opening round in Rome, faces either Swiss Romina Oprandi or Germany's Andrea Petkovic in round two.