Ivan Ljubicic retires from professional tennis after a stellar career which included 10 titles . The 33-year-old was also part of Croatian Davis Cup team which beat Slovakia in 2005 . Says Djokovic displayed mental strengths as a youngster but was not the best technically . Score: 6
Ivan Ljubicic retires from professional tennis after a stellar career which included 10 titles . The 33-year-old was also part of Croatian Davis Cup team which beat Slovakia in 2005 . Says Djokovic displayed mental strengths as a youngster but was not the best technically . Ljubicic claimed ATP Indian Wells Masters title at the age of 31 in 2010 .