Former world squash champion Gregory Gaultier will miss the rest of the season after undergoing knee surgery.
The Frenchman, also a former world number one, is now aiming to return in 2019.
He has withdrawn from the Qatar Classic, a tournament he won in 2011 and which is due to begin this year on October 27.
Gaultier injured his right knee during his quarter-final clash with Egypt's Ali Farag at the US Open earlier this month.
No exact timescale has been given on when he can return to the court.
The 35-year-old won his world title in 2015 in Bellevue in the United States.
He beat Egypt's Omar Mosaad in straight games in the final after previously being the runner-up on four occasions.
Gaultier has also won the prestigious British Open three times and won the World Games gold medal in Cali, Colombia, in 2013.