Just a few short days after withdrawing from the Brisbane International ahead of the official start of the 2015 season, Marin Cilic has officially announced that he is unfit to participate in the season-opening Grand Slam event in Melbourne.

“I am really disappointed to announce that I had to withdraw from the Australian Open,” Cilic announced on his website. “It is a right shoulder injury, that hampers me for some time now and forced me to withdraw from the ATP World Tour event in Brisbane. It is improving day by day, but I still don’t feel fit enough to be able to compete at the highest level.

The reigning US Open champion is a former semi-finalist at the Australian Open (2010), where he lost to tournament runner-up Andy Murray. After only playing a few matches at the IPTL during the off-season, it now appears that the shoulder injury that limited his playing then has only gotten worse over the following month.

With his withdrawal, Cilic joins Radek Stepanek, Tommy Haas, Janko Tipseravic and Jack Sock as early victims of the injury plague.

“I am really sad that I won’t be able to participate in Melbourne, especially after winning the last Grand Slam in New York, but I was advised by doctors to be careful as much as possible to avoid even more serious problems.

“I have received lots of support letters from my fans worldwide lately and I am grateful for your support and best wishes. I was really looking forward to being back on court in Australia and now I hope we will meet very soon in Zagreb.”

James Ward will replace Cilic in the main draw of the tournament.