Serena Williams says she will be praying for Jennifer Capriati after the American was taken to hospital in Florida after an accidental overdose of prescribed medication.
The 34-year-old, who has not played on the tour since 2004 due to injury, is expected to make a full recovery.
Capriati has reportedly been suffering from depression and Williams said: "I will pray for everyone involved. If there's any way I can do anything to help, I definitely will do that."
Capriati's career was derailed by personal problems in the early 1990s, including a shoplifting incident and arrest for marijuana use. But she returned in 2001 to win the Australian Open and French Open, before a second win in Melbourne the following year.