premise: Wang Liqun, deputy director for the event jointly held by the International Tennis Federation (ITF), the world governing body, and the ATP, had promised Tuesday that tennis fans will be compensated for the withdrawals and absentees of tennis masters.
  "Fans who have already bought tickets for this tournament will be able to enjoy a discount next year in the Tennis Masters Cup with no price raising," said Wang.
  By the same token, the ATP has also promised that in the next three to six months, some of the top-notch or first-class tennis players will come to Shanghai to meet fans and endorsers.
  The Masters Cup, which is always at risk of absenteeism as it comes at the end of the season, has been without five of the world's leading six players after only the second day.
  World No. 2 Rafael Nadal Monday announced his pulling out with a left foot injury before his Masters debut even started, and minutes later Andre Agassi further long line of withdrawals at the ATP season-ending event, blaming a bad ankle sprain sustained playing racquetball.
   What caused Andre Agassi to withdraw from the Masters Cup?
hypothesis: come to Shanghai