The majority of the Indonesian team has pulled out of the competition after the country's badminton association expressed concerns over COVID-19.

In a statement, the Badminton World Federation (BWF) said it was "disappointed" with the Badminton Association of Indonesia's decision and criticised the fact it was announced after the draw for the event had been made.

"The BWF and the Spanish Badminton Federation are now focused on delivering a safe and successful World Championships in line with the advice and measures put in place by the local and national health authorities, including a comprehensive set of safety protocols for all players, team officials and key stakeholders," the BWF said.

Top seed and defending champion Kento Momota of Japan has also withdrawn from the Championships, scheduled to conclude on December 19, due to an injury he sustained at the recent BWF World Tour Finals.

Momota, the world number two, had been scheduled to open his men's singles campaign against Poland's Michal Rogalski tomorrow.

Three-time women's singles champion Carolina Marín will not be competing at her home World Championships after being forced to pull out with injury.

The Rio 2016 Olympic gold medallist has been unable to recover completely from a left knee injury she sustained earlier this year.

"Mentally it has been really hard to keep myself up," Marín said in a video statement.

"My priorities have always been health and wellbeing. 

"Therefore my team and I have decided not to play the World Championships, and we have also taken the decision of not having a formal date of comeback to competition until we are 100 per cent sure that my knee is fully recovered. 

"So we will be evaluating the progress of the knee and the sensation I’m having with it daily. 

"We believe I might be officially playing again in February or March."