A post-mortem examination has confirmed that Phil O’Donnell, the Motherwell captain, died of heart failure. O’Donnell, 35, collapsed during Saturday’s Clydesdale Bank Scottish Premier League game against Dundee United. “The post mortem revealed that Phil had suffered left ventricular failure of the heart,” Dr Robert Liddle, the club doctor, said. O’Donnell’s funeral service will take place in Hamilton on Friday at noon.

Gary Caldwell, the Celtic defender, has called for research into the effects of food supplements and energy drinks on players after a series of deaths. “I have thought about it,” Caldwell said. “You drink energy drinks, you take supplements and you do it to become a better player. But I think somebody has got to look into it and try to see if it does affect you.

“We are all distraught and it’s a hard time for everyone at the minute. I think everyone’s thoughts are just with Phil’s family and Motherwell.”

In 2003, Marc-Vivien Foé, the Cameroon midfield player, died at 28 after suffering a heart attack during the Confederations Cup semi-final against Colombia in Lyons. Last August, Antonio Puerta, 22, the Seville defender, died after a heart attack during the 4-1 win against Getafe.