Sohrab Moradi, one of the world's best weightlifters who was seen as a strong favourite to win a second Olympic gold medal next year, is likely to miss Tokyo 2020 because of a serious back injury suffered in training this week.
Moradi, who broke the longest-standing world record in the sport last year, must undergo immediate spinal surgery.
A spokesman for Iran's Sports Medicine Federation said that after surgery Moradi "needs to rest for at least six to nine months, but we will try to prepare him for Olympic qualification".
That will be extremely difficult, as Moradi would have to compete by the end of October to be eligible for Tokyo.
He is already ruled out of the Fajr Cup qualifying competition in Iran next month, and the Asian Championships in Ningbo, China, in April.
Moradi, who won Olympic gold at Rio 2016, is also likely to miss the 2019 World Championships in September, said the Sports Medicine Federation.
Only on Monday (February 11), Moradi was named runner-up behind Lasha Talakhadze in the International Weightlifting Federation Weightlifter of the Year awards.
The 30-year-old won gold in the new Olympic weight category of 96 kilograms at the 2018 World Championships in Turkmenistan last November, a few months after winning Asian Games gold at his previous weight of 94kg.
In that Asian Games win, Moradi snatched 189kg to break a world record that had stood since 1999, set by triple Olympic champion Kakhi Kakhiashvili.
Another big name in Iranian weightlifting, Kianoush Rostami, returned from a long injury lay-off last week to win the 96kg class at the EGAT's Cup in Thailand - also an Olympic qualifier.
Rostami, the 2016 Olympic champion at 85kg, totalled 371kg, which is 45kg less than Moradi's winning total at the World Championships.