The American former world number one said skipping her final planned US Open tuneup was necessary for her to be able to play her best when the year's final Grand Slam event begins in New York on August 28th.

"Unfortunately, my knee is just not acting right," Williams said. "It's just not supporting me being on the court right now. It's such a bummer."

Williams indicated a desire to play next year in Cleveland, a sign she looks to compete again in the 2024 WTA campaign.

"I'm going to work on myself, try to get myself together, so that way I can be at the Open, and also, hopefully, come and play (Cleveland) next year," she said.

Williams received a wildcard spot into the Cleveland field as well as into the US Open, where she is set to make her 17th main draw appearance.

Williams captured her first triumph over a top-20 foe in four years when she beat Veronika Kudermetova at Cincinnati and was up a set and a break before making a second-round exit.

Mirra Andreeva, 16, was to have played Williams in her Cleveland opener but instead will now face German lucky loser Tamara Korpatsch.

"I'm so sorry that I'm not going to be able to make it to Cleveland," Williams said. "I was really looking forward to it."

Williams, ranked 407th in the world, won the 2000 and 2001 US Open titles and captured five Wimbledon singles crowns, the most recent in 2008.