Rafael Nadal and Carlos Alcaraz have pulled out of the Monte Carlo Masters, which begins on April 8.
Tennis great Nadal is suffering from a hip injury, meanwhile world number two Alcaraz has post-traumatic arthritis in his left hand along with muscular discomfort in the spine.
"Hi everyone, I´m still not ready to compete at the highest level," Nadal tweeted.
"I will not be able to play in one of the most important tournaments of my career, Monte Carlo."
The Monte Carlo tournament, which Nadal has won 11 times, was a chance for him to prepare for the French Open, which starts May 28.
Nadal said he was hoping to return soon from the hip flexor injury he sustained in the Australian Open in January, suffering a second round exit against Mackenzie McDonald.
The 22-time Grand Slam champion pulled out of hard-court tournaments at Indian Wells and Miami, with his sights set on a return at the start of the clay court season.
Record Monte Carlo Masters champion Nadal won the tournament eight consecutive times between 2005 and 2012.
After the tournament´s director said Nadal was registered for this year´s edition, the Spaniard last week denied he was set to participate.
"I don´t know who gets this information, but obviously if it were true, I would confirm it, but, unfortunately, I cannot confirm it," said Nadal at an event.
"Things are moving day by day, and I don´t say things that I can´t fulfil."
Meanwhile, Alcaraz also shared the news about pulling out of the tournament on his official Twitter account.
“After two months abroad, I am happy to return home but sad because I finished my last match in Miami with physical discomfort. After visiting my doctor in Murcia today and being evaluated, I will not be able to go to Monte Carlo to start the clay court tour,” Alcaraz tweeted soon after Nadal’s withdrawal.
“I have post-traumatic arthritis in my left hand and muscular discomfort in the spine that needs rest to prepare for everything that is to come,” he added.
World number seven Felix Auger Aliassime has also withdrawn from the event due to a left knee injury.
“I have been struggling with my left knee for the past few weeks and decided it was the smartest decision to take some time off so I’m able to fully heal and recover before my next tournament Madrid Open,” Felix said on his official Instagram account.
“Thank you as always for your support and I look forward to seeing you back on court soon,” he added.