Serena Williams talked with USA Today on Tuesday about her recent health scare and how she has been depressed during her time off the court.
"I definitely have not been happy," she said. "Especially when I had that second surgery (on my foot), I was definitely depressed. I cried all the time. I was miserable to be around."
The 13-time major winner suffered a pulmonary embolism earlier this month, shortly after her cast was removed from her right foot.
Williams, who hasn't played a match since winning Wimbledon in July, went on to say that she is unsure when she will return.
"I don't know what's realistic," said Williams. "I really don't know. I haven't put a date on it yet. I know how to play tennis. I've been doing it for a long time--longer than I can say. So I figure that will work out.
The 29-year-old had to undergo two surgeries on her right foot after cutting it on glass.