Even having acquired Chinese passports, some of the country's naturalized players, such as Guangzhou Evergrande's Brazil-born striker Ricardo Goulart, have been told by clubs to stay put due to the reduction in the number of international flights departing for China and the risk of infection during long trips.

From Sunday, China's domestic airlines are required to cap their international routes to one flight per country per week, according to the Civil Aviation Administration.

Former Manchester United midfielder Marouane Fellaini became the first CSL player to return a positive test for the virus upon his arrival in China on March 22, and the Belgium international is now under quarantine.

The severe threat from imported COVID-19 infections, as highlighted by the Fellaini case, coupled with the latest entry restrictions, has sparked renewed caution over proposals to resume domestic league action, despite effective virus containment at home.

The General Administration of Sport of China, the country's top sports authority, has called off plans to restart the CBA season on April 15 with behind-closed-doors tournaments in light of the latest developments, according to Beijing Youth Daily.

The CBA is now exploring a contingency plan to allow each team to use only one foreigner on court at any given time, down from two earlier this season, if the league is allowed to resume before the travel ban is removed, added the report. With some teams hit harder than others by the absence of foreign stars, the idea is designed to level the playing field as much as possible.

Still, some of the league's highest-profile foreign employees, including the Beijing Ducks' American guard Jeremy Lin and Beijing Royal Fighters coach Stephon Marbury are back in China and raring for tip-off.