"She played unbelievable today and she was everywhere and she hit all the balls in a very strong, very powerful way," the world No.2 said after the match. "It was a little bit cold and I couldn't be at my best."
The 33-year-old had scored 45 goals in 68 games and won two A-league championships since he joined the Sky Blues in August 2018.
"I need to improve my physical condition and experience," she told Xinhua, after finishing with 17 points, eight rebounds and seven assists against Shanxi.
Union gained momentum but missed the chance to extend the lead at the half-hour mark after Nico Schlotterbeck pulled wide from tight angle.
2. Neymar has Ronaldo, Pele in his sights
Osasuna didn't play in midweek as its scheduled match against Granada was postponed to allow Granada to play in the Europa League, and the side from Pamplona should be fresher than Celta Vigo, who travels to the remodeled El Sadar Stadium after losing 3-0 at home to Barcelona.
The 19-year-old Pole needed just 68 minutes to avenge her exit to the 2018 champion last year in Paris at the same stage.
Cavani was left out of the Celeste squad by head coach Oscar Tabarez, paying the price for having not played since March.
Her former teammate in Beijing, Shi Xiufeng, showed an eagerness to return to court.
The injury means that Alba will be forced to pull out of the Spanish national team squad for the forthcoming friendly game in Portugal and the UEFA Nations League ties against Switzerland and Ukraine.
"We're focused on the fact that we're really looking now at January 1 to start the season up. Our hope is to have a full season, full regular season, and to have fans in the building, but there are a lot of things that have to transpire, many of which, if not most of which, are beyond our control, before we can finalize our plans," Commissioner Gary Bettman said on Tuesday.