The Rubronegro have remained in Ecuador ahead of Tuesday's clash in the Pacific port city of Guayaquil.
All three are asymptomatic.
Yuan looked as if she thought the game was over after the second set, but it was in the third set where Yunnan staged their strongest resistance.
In Sunday's other Serie A matches, Genoa crushed newly promoted Crotone 4-1 while Sassuolo tied with Cagliari 1-1. Enditem
The three-time world champion will face Martin Gould in Sunday's final, after the world number 53 stunned world number one Judd Trump 6-3 in the other semifinal.
Yu Jingyao from Beijing and world champion Fu Yuanhui had the same trouble as Yu.
Fans and half of the club are puzzling about who could be the rescuer leading the side out of this deep crisis. Former Schalke and Leipzig coach Ralf Rangnick is one name in the list.
Chengdu was the only side who had pocketed three wins consecutively in the first three rounds of the league.
"One can't understand it," Flick said when criticizing UEFA's decision to choose the venue and allowing up to 20,000 spectators.
RIO DE JANEIRO, Sept. 20 (Xinhua) -- A stoppage-time goal from substitute Aldemir Ferreira earned Gremio a 1-1 home draw with Palmeiras in Brazil's Serie A championship on Sunday.
South American football governing body CONMEBOL is understood to have ruled out the possibility of postponing the fixture. The entity's coronavirus protocols required clubs to register 50 players in their Copa Libertadores squads to help teams with several coronavirus cases.