Swimming Australia has confirmed that James Magnussen will not compete in this July's World Championships in Russia due to a shoulder injury.
The 24-year-old was due to defend his 100m freestyle gold in Kazan, but scans have shown that surgery is required as the double world champion's strength has been reduced by 70% because of the injury.
The decision has been taken by Swimming Australia as they hope to keep Magnussen on track for the Rio Olympics in 2016.
A statement from Magnussen read: "I will now focus all my time and effort on preparing for the Olympics next year. I am looking forward to regaining full strength in my shoulder and getting back to my best performances."
Magnussen will be replaced in the 50m and 100m freestyle, as well as the 4x100m freestyle relay.
