Serena Williams has insisted that she will only return to the court when she feels 100% fit.
The 22-time Grand-Slam champion took the Wimbledon crown earlier this year, but failed to add to her impressive trophy cabinet at the Australian, French and US Opens.
Williams also lost her number one world ranking to Angelique Kerber after she was knocked out in the semi-finals at Flushing Meadows.
"I'm tired of playing tournaments unhealthy and taking losses that I would never lose," Williams told CNN.
"I definitely want to make sure I'm healthy and playing at my best or at least 80% healthy or 70% healthy - that way I can be able to play at a higher level."
In the past year, Williams has struggled with shoulder and knee injuries.
