Ivanovic, 20, officially took over the top spot in the world's women's rankings Monday but had locked it up with a French Open semifinal victory last week. She went on to win the French Open championship, her first grand slam title.
But Wednesday she said she wouldn't play in next week's International Women's Open in Eastbourne, England, because of injury. That event is played on grass courts and is a final tuneup ahead of Wimbledon, which begins June 23.
In an entry on her Web site, Ivanovic said she was sorry not to be playing at Eastbourne but in addition to the abductor issue: "I am also mentally exhausted after the French Open -- I am not ready to compete so soon after winning my first Grand Slam. I have taken this decision with some regret and I hope I can finally play in Eastbourne next year."