Sydney - Australia's world 100m freestyle champion James Magnussen on Tuesday said he was splitting with long-time coach Brant Best to get a fresh start heading towards the 2016 Rio Olympics.
The 23-year-old, who is battling a persistent back injury, said he wanted to reinvigorate his training programme and was looking for a new mentor.
"Brant has been such an important part of my journey as a professional swimmer, and in shaping me as a person," he said in a statement to the Australian Associated Press.
"Those things combined have made this decision incredibly difficult.
"As I launch into this next competitive block, I have resolved that in order to refocus my programme, and to achieve a sense of renewed invigoration, part of that change process involves working with a new coach."
Under Best, Magnussen won world titles in 2011 and 2013 and claimed silver in the 100m freestyle at the 2012 London Olympics.