Serena Williams
Well, did you know they are friends? Most didn’t. We didn’t. Have you ever seen a picture of the two frequently hanging out together? No. But apparently, Serena promised Kim some tennis lessons to keep her fit for the Nets basketball star.Tennis player Serena Williams arrives at the 2011 Vanity Fair Oscar party in West Hollywood Reuters is reporting that tennis star Serena Williams suffers from a pulmonary embolism.

The 29-year-old athlete has been spotted at Cedars-Sinai Medical Center in Los Angeles a number of the times in the past week. reports that Williams's rep, Nicole Chabot, confirmed the athlete's heath status.

Monday Serena Williams underwent emergency treatment at Cedars for a hematoma she suffered as a result of treatment for a more critical situation, that rep told

Last week, Serena suffered from a pulmonary embolism [a blood clot in the lungs] which was discovered upon her return to L.A. She had been in New York for doctor appointments for the ongoing issues with her foot. Doctors are continuing to monitor her situation closely to avoid additional complications.

The tennis star was last seen Sunday night at Elton John's Aids Foundation Academy Award Viewing Party.