Serena Williams tweeted on Tuesday she's back on court training after a series of health problems that included dangerous blood clots in her lung.
"Look who I spotted on the court. Her first day back... " the 13-time Grand Slam champion said in a posting on her @serenawilliams Twitter account.
She also posted a picture of herself in mid-serve, wearing a bright pink body suit that gleamed in the sunshine.
Williams has not played a top-level match since last year's Wimbledon final.
Shortly after that triumph, she cut her right foot on broken glass at a restaurant last July.
She required two operations on her foot, and in February suffered a pulmonary embolism that led to an emergency procedure in Los Angeles.
Williams, 29, hasn't said when she will return to the WTA tour. She would need to be ready by June 20 to defend her Wimbledon title.