BEIJING - The Chinese Basketball Association (CBA) has issued a warning to Liaoning Flying Leopards guard Guo Ailun for violating COVID-19 containment measures.

CBA revealed that on Sunday morning, Liaoning's manager, players and Xinjiang Flying Tigers staff, all with green credentials, were permitted to see off Liaoning's departing head coach Guo Shiqiang outside their hotel in Qingdao, one of two competition sites for the CBA's resumption.

However, Guo and Xinjiang's team doctor Jiang Hongjun didn't wear masks during the period as required.

To safeguard all participants, the league has dispatched credentials of different colors to different groups. Players, coaches and referees are offered green credentials, while yellow and blue credentials are provided to reporters and staff in the arena respectively. People in the green area cannot conduct any close contact with those having credentials in other colors.

The league has issued a warning to Guo and Jiang for their breach of anti-virus regulations, adding that any further violations could lead to a one-match suspension and even disqualification.

The CBA also calls on all participants and staff to strictly abide by relevant COVID-19 containment measures, and make their own contributions so that the resumed league can operate smoothly.

Guo, a member of China's national team, averaged 20.0 points, 3.6 rebounds and 4.7 assists in 26 matches this season.