Cape Town - Australian Open semi-finalist Stan Wawrinka has been forced to pull out of next week's ABN Amro World Tennis Tournament in Rotterdam due to a knee injury.
The news was confirmed by tournament director Richard Krajicek, citing the knee injury that the Swiss struggled with during the Australian Open as being the reason for his withdrawal.
"Stan called me this afternoon to share the bad news. Test results today showed that he is not able to play matches as a result of his knee," said Krajicek.
"The medical advice came as a complete and unpleasant surprise. Not just for us, but for him as well."
The US Open winner will be replaced by Frenchman Benoit Paire, while 14-time Grand Slam winner Rafa Nadal of Spain will replace Wawrinka as the top seed for the tournament, which runs from February 13-19.
The rest of the field is a strong one with the likes of Marin Cilic, Dominic Thiem, Thomas Berdych, David Goffin, Jo-Wilfried Tsonga and Grigor Dimitrov also scheduled to play.