An elbow injury will sideline Kevin Anderson for the entire clay-court season, including next month's French Open, he announced on social media.
"After discussing with my doctors and team, we thought the best decision is to rest and rehab my elbow injury for a few more weeks," Anderson wrote.
"I'm very disappointed to be missing Estoril, Madrid, Rome, and Roland Garros - all incredible events that have been so great to me and I love going back to - but I know this is the right decision for the long term in my career."
The No. 6-ranked player in the world has competed in only one tournament since the Australian Open and just three overall this season. Anderson kicked off the year by winning the Maharashtra Open in India and was a quarterfinalist at last month's Miami Open.
The hard-serving South African has arguably played his best tennis over the past two years. Anderson made his first Grand Slam final in 2017 at the US Open and made a second less than a year later at Wimbledon. He's also made back-to-back fourth-round appearances at the French Open over that same span.
Anderson reached a career-high ranking of No. 5 last July.