Croatia's Mario Ancic has confirmed he will miss both Wimbledon and his country's Davis Cup clash with the United States due to illness.
The 25-year-old has still not regained full fitness having been struck down with glandular fever two years ago and has now opted to take a break from the game.
Ancic, ranked at 38 in the world, has won 13 of his 20 singles matches this year and reached the final of his home ATP event in Zagreb.
However, he has been struggling with form and fitness of late and recently pulled out of the French Open.
He will now also miss Wimbledon, where he reached the semi-finals in 2004 and the quarters in 2006 and 2008, and admits he is unsure when he will return to action.
"Don't ask me when I'll return, because I don't even know the answer myself," Ancic told the press in his homeland. "Health is most important. I have to listen to my body.
"The fact that I cancelled my favourite tournament (Wimbledon) and an important match with Americans, tells it all about the seriousness of the situation."