More than 1,400 footballers have died this season from heart failure, with the number rising to nearly 30 this week.
The Football Association said that while the number of heart failure cases has fallen to 1,936 from a peak of nearly 1,000 in February, the number has continued to rise.
As of Friday, more than 5,500 people were in hospital due to heart failure.
An estimated 1.5 million people worldwide are affected by the condition, with 1.3 million deaths from it.
The World Anti-Doping Agency (WADA) said the number had more than doubled from a previous peak of 5,000 cases in 2017.WADA Chief Executive Olivier Niggli said the increased number of cases had been linked to an increase in the number and intensity of drug-related incidents and deaths.
“We are currently at a high risk of the spread of the coronavirus, which is currently being spread by athletes, who are taking a high-risk course of action to protect themselves,” he said.
“This has resulted in more than 30 deaths in the UK alone and has also increased the risk of infection.”
While it is not a complete picture, it does reveal the worrying trend of increasing numbers of individuals contracting the virus and not getting tested for it.
“The figures come a day after Premier League footballer Samir Nasri died after suffering a heart attack during training in Spain.
He was aged 37.
A video posted on social media showed Nasri, who had recently been released from hospital, standing over a dying woman as he lay on the ground, with a white sheet covering her face.
He said he was “sick of seeing” the images and wished “that the whole world could stop the suffering” of his friends and family.
The Premier League said Nasri had been diagnosed with a heart condition and would have been a member of its medical team.