"But I take it as a very positive thing. I am playing quite well to win against a player like Stefano today with this score.
Sunday's rivals are Europa League champions Sevilla, and Koeman's big issue is in defense thanks to the red card shown to Clement Lenglet against Celta on Thursday.
Shandong built a 17-7 lead at the beginning of the second set, while Tianjin found it difficult to erase the deficit.
"We didn't handle some big shots well due to a lack of experience," admitted Wuhan coach Li Xin. Enditem
"We put on a good defense, both with and without possession, but admittedly there is a gap separating the two sides," he noted. Enditem
The win also improves the Serbian's season record to a stunning 34-1. The only defeat came in a disqualification earlier this month at the US Open, where he hit a ball in frustration which struck the line judge on the neck.
"It was a very even match, perhaps more difficult than the result showed," said Djokovic, who is seeking for an 18th Grand Slam title.
"The match today I think we both play really well and a really great match. She played unbelievably good," said Zhang, who defeated Burel 6-3, 7-6(3) in the Strasbourg Open before coming to Paris.
The two-time Grand Slam winner committed just seven unforced errors throughout the one-sided encounter and broke her opponent's serve six times.
Elsewhere, Svit registered its first victory of the new season, winning in Handlova 89-81 on Saturday.
"All the time I kept myself in the back to attack when I needed to," said Kitata. "When I went, I tried to push the pace more than before. I went into the last lap to beat the others."