Djokovic said he will bypass the Serbia Open -- which is organized by his family -- due to last week's death of his grandfather.
He was coming off a one-sided defeat at the hands of formerly top-ranked Rafael Nadal in the finals of the Monte Carlo Masters, and Djokovic said the death of his grandfather was weighing on his mind at the time.
"This was one of the most difficult decisions in my career, but it is impossible for me to play and think about tennis," Djokovic said of his decision to withdraw.
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