Serbian world number two Novak Djokovic has pulled out of the Miami Open with a right elbow injury, the tournament's three-times reigning said on Sunday.
The injury is the latest setback for Djokovic, who has suffered a drop in form since completing a sweep of the grand slam titles at last year's French Open.
"My doctor has strongly advised against play because my elbow injury, that I keep carrying on for months, got worse in the past week," Djokovic said on the tournament's website.
"I will do everything in my power to recover and do all the necessary therapy to be able to return on court as soon as possible. Sadly, I won't be able to defend my title in Miami this week."
Djokovic, who has won a record-tying six titles in Miami, joins world number one Andy Murray on the sidelines of the hardcourt event as the latter withdrew on Saturday, also citing a right elbow injury.
The 29-year-old Serb was beaten by Nick Kyrgios last week in the fourth round at Indian Wells, marking his second loss to the Australian in less than two weeks.
Djokovic described it as "shocking" that he would have to miss the March 20-April 2 Miami event, where he won his first Masters event before making his ascent toward the top of the world rankings.
"No wonder they say that in sport the biggest and most painful defeats come from injuries, and not from opponents," said Djokovic.
"I am lucky that throughout my career I didn't have many injuries, but I guess that all that I've been through physically in the past so many years did leave a mark on my body."