Motherwell captain Phil O'Donnell died of heart failure, a post mortem examination has confirmed.O'Donnell, 35, collapsed during Saturday's Clydesdale Bank Premier League game against Dundee United. Dr Robert Liddle, the club doctor, said: 'The post mortem revealed that Phil had suffered left ventricular failure of the heart.' O'Donnell's funeral service will take place in Hamilton on Friday at noon. The requiem mass, in St Mary's Church, Cadzow Street, Hamilton, will be followed by internment at the nearby Bent Cemetery. At the request of his wife Eileen, the church service will be for all the family and his many friends. Directors, management and employees of Motherwell Football Club as well as representatives of other football clubs and football organisations are welcome. The mass will be celebrated by parish priest Father Henry O'Brien. Given the limited number of seats within the church, many fans will be unable to attend the service. Those fans and admirers will be able to show their respect as the cortege leaves the church on its way to Bent Cemetery. Following the internment, the family, friends and other guests will all attend a reception at Fir Park. Meanwhile, O'Donnell's widow has today spoken publicly for the first time since his death on the field. Mrs O'Donnell said she has been left 'devastated' by her husband's death, adding that he would want to be remembered as a family man. Mrs O'Donnell, mother of the couple's four children, visited a makeshift tribute created by fans of scarves, strips and pictures at Motherwell's Fir Park ground yesterday. And she said today: 'Although he achieved so much in football the most important thing for him was his family. 'He would like to be remembered as a family man and we were all so proud of him. 'We are all devastated by what has happened. 'We hope we will now be given peace and time to grieve but we are overwhelmed by the messages of support we have received.'