England boss Gareth Southgate is to take part in a study exploring the links between football and dementia and has urged other former professionals to do the same.
The 50-year-old has volunteered to join the HEADING study, led by the London School of Hygiene & Tropical Medicine.
A second independently led study by the University of Nottingham, called FOCUS, is being backed by funding from the Football Association and Professional Footballers' Association.
It is hoped the research can further understanding of possible links between professional footballers and an increased risk of neurodegenerative disorders. Former England international Nobby Stiles had dementia when he died last year, while fellow 1966 World Cup winner Bobby Charlton has the disease.
"This is an incredibly important issue in our game and I'm very happy to play my part in supporting this research," Southgate said via the FA.
"Having turned 50 last year, I am now eligible to take part in the HEADING study, which could provide crucial and valuable insight to help people who play the game now and in the future.
"I would encourage any former professional footballer who is willing and able to take part in the HEADING or the FOCUS study to do so.
"Our involvement is absolutely essential if we are to have a greater understanding of this issue;