Darren Clarke (left) and Tiger Woods are close friends

Woods took time off from preparing for the defence of his Open crown at Royal Liverpool to reflect on the Ulsterman's sad predicament.

"The fact he has been in contention the last couple of weeks has been absolutely remarkable," he said.

"God, the things that he's going through, I truly feel for him."

Woods added that it was "not fun for anyone to watch someone you love deteriorate right in front of you".

"For him to have to go through it and the way he has dealt with it has been absolutely remarkable.

"It shows the character and the type of person he is."

"You watch that each and every day, it's very, very difficult to handle."

The 30-year-old's father Earl died in May after a long battle with cancer.

Woods took nine-weeks off to mourn and only returned to action at last month's US Open where he missed the cut in a major for the first time in his career.

Clarke and Woods have been close friends for several years.