Serena Williams says she is still aiming to play Cincinnati, despite retiring from the Rogers Cup final in Toronto with a back injury.
The No. 8 retired at 3-1 down against Bianca Andreescu, but said the problem was usually temporary and she still plans to compete in a few days.
"Yeah, it started yesterday in my match and it just got worse. Just my whole back just completely spasmed," she said. "That's the most frustrating part is that, I mean, I've had this before and it's, like, 24, 36 hours where I'm just in crazy spasm and then it's, like, gone.
"So I do different treatments. I take a day off. But obviously, I didn't have 24 hours or plus to take off."
If the injury improves like it usually does, added Williams, she should be fine for Cincinnati.
"As of now, I'm going to go to see what happens," she said.
Williams retired from the Rogers Cup final with a back injury on Sunday. (Getty Images)
But tournament champion Andreescu did withdraw from Cincinnati, having played four three-set matches and experienced a groin pull during her quarterfinal. She was playing her first event since the French Open because of previous shoulder problems. In a statement, Andreescu said she had to listen "to her body right now," noting her tough week in Toronto.
Nadal, who won the Montreal Masters, also withdrew from Cincinnati citing fatigue. He had said he would play Montreal and then decide whether to play again the following week, scheduling with caution because of numerous injury withdrawals and retirements from recent hardcourt events.
Novak Djokovic and Roger Federer, who did not play Montreal, are playing Cincinnati, where Andy Murray makes his singles comeback.