Olympic 1,500m winner Taoufik Makhloufi of Algeria pulled out of next month's world championships in Moscow due to a viral infection.
The 25-year-old has not trained for the past month, reports Xinhua.
Makhloufi became the latest big name to miss the worlds following the withdrawal of Kenya's world and Olympic 800m champion David Rudisha and Jamaican world 100m champion Yohan Blake due to injuries.
Meanwhile, US sprinters Tyson Gay and Jamaican Asafa Powell have been ruled out after failing drug tests.