Ethiopia's Kenenisa Bekele will not launch a bid for double gold in the 5,000m and 10,000m at August's Olympics.
Bekele won the 10,000m world title in Paris last year
Bekele, who sealed a hat-trick of double world cross-country titles at the weekend, had been tipped to compete over both distances in Athens.
But on Tuesday he said he would focus on just one event.
"It will be my first Olympics and we can expect very hot weather so, having all this in mind, I will run only one event there," he told the IAAF website.
"There is no room for a double. Which event will it be? I will know after the early season races."
The 21-year-old has already triumphed over the 10,000m on the world stage, winning the world title in Paris last year.
He outsprinted countryman Haile Gebrselassie to win gold but said he was unfazed by any competition in either the 5,000m or 10,000m.
"One thing is sure - I will not decide based on the names which will be running," said Bekele.