CHINA’S Sun Yang was a shock late withdrawal from the final of the men’s 1,500 meters freestyle at the world championships Sunday. Sun, the reigning world and Olympic champion and world record holder, was the hot favorite for gold but did not show up at the starting blocks despite having warmed up for the race.

    The 23-year-old said he made the decision to pull out shortly before being called to the Kazan pool having felt unwell during the warmup.

    Sun explained he started feeling problems with his heart after retaining his 800m freestyle world title Wednesday.

    The same problem in his chest returned while he warmed up for Sunday’s 1,500m final.

    “First of all, I am very sorry that I couldn’t swim the 1,500m final,” he said in a press conference.

    “After the 800m competition, I didn’t feel well in my heart. I felt uncomfortable in the warmup tonight so I had to give up the idea of competing.”

    His withdrawal meant Sun missed out on repeating his 2013 sweep of the 400, 800 and 1500m freestyle world titles having already won last Sunday’s 400m final.

    The Chinese giant courted controversy in 2014 after it emerged he had served a three-month doping ban for taking a banned stimulant.

    Trimetazidine was in a prescription drug he sometimes took for heart palpitations.

    Sun said it was the first time he had been affected like this and he wanted to get to the bottom of the problem as quickly as possible.

    He said he would be seeking medical advice as soon as he gets home.

    “Yes, this is the first time I have felt uncomfortable with my heart in a competition,” he said as Italy’s Gregorio Paltrinieri won the 1,500m world title in his absence.

    “I will go back to China tomorrow and will arrange to have a complete check of my heart as soon as possible.”

    As Sun left it until the very last minute to withdraw from the race, his lane remained empty for the final as swimming’s governing body FINA had no time to call up reserve Pal Joensen of the Faroe Islands.

    “I made the decision by myself and didn’t tell my coaches, as I said I am very sorry,” said Sun.

    “After the warmup, and while I was preparing to take part in the competition, I realized I just couldn’t compete. I didn’t see what time it was.”

    Brazil men’s coach Alberto Silva said there was an incident in the warmup pool Sunday morning when one of his female swimmers was in the same lane as Sun, though Silva did not think it was the reason why Sun didn’t compete.

    “There was a discussion,” said Silva, adding that no one was injured.

    Silva said he complained to officials of the world governing body FINA, and they spoke to a Chinese team official.

    “(The Chinese) came to the Brazilians and said sorry. That’s it,” said Silva, who declined to identify the Brazilian swimmer.

    Brazil team spokeswoman Eliana Alves said there was contact between Sun and the Brazilian athlete “but it was not a fight.”

    Chinese team officials declined comment on the warmup pool incident.

    “I have no comment because it’s the morning program,” Sun said. Sun appeared at the end of the night to receive the best male swimmer award.

    Katie Ledecky of the United States won the best female swimmer award.(SD-Agencies)