BELGRADE, Serbia -- Novak Djokovic's Serbia Open has been dropped from the ATP calendar.

The tournament has failed to attract top players or major sponsors. Last year, even Djokovic and other top Serbian players failed to attend.  
Djokovic's Family Sport, the tournament organizer, says it "made the most rational decision considering the circumstances."  
The tournament had been scheduled this year for April 29 to May 5. The event was first held in 2009 and has been bought back by the ATP.  
The Serbia Open was the only ATP tournament held in Serbia.