TORONTO - With more than 500 people offering to give part of their liver to Ottawa Senators owner Eugene Melnyk, one of his doctors is now saying he could undergo surgery by the end of this week.

Dr. Atul Humar, Director of the Multi Organ Transplant Program at Toronto General Hospital, said there has been a "huge response" to Melnyk's urgent public appeal for a liver transplant.

The Senators announced on Saturday that more than 12 candidates have been identified and selected to go through the donor screening process. The candidates are all at different stages of that process.

Melnyk, 55, who has been battling health issues for months, was admitted to hospital three weeks ago due to the onset of liver-related complications. His condition is considered critical.

Melnyk had been reluctant to make a public appeal, but loved ones convinced him to reach out for a potential donor after members of his family were found not to be suitable. A living donor transplant is Melnyk's best option because he has rare AB blood; a live donor doesn't need to have a matching blood type, whereas an organ from a deceased donor must be a perfect match.

Humar said doctors hoped the transplant would take place toward the end of the week. Dr. Gary Levy, director of the living donor liver transplant program at Toronto's University Health Network, said on Friday the transplant team hoped to have a donor match for Melnyk within 72 to 96 hours.