Williams injured her Achilles tendon during her semifinal loss to Victoria Azarenka at the US Open earlier this month.
The Spaniard will next take on 18th seed Grigor Dimitrov of Bulgaria, who beat Slovakia's world number 102 Andrej Martin 6-4, 7-6, 6-1.
Yao was the title favorite but the 30-year-old failed to clear the bar at 5.30m, although he passed the height of 5.15m in his first attempt.
"To make things easier I told the players yesterday [Wednesday] that this was the right way to go," he added, suggesting the decision was of his own volition.
MEXICO CITY, Oct. 1 (Xinhua) -- Wolverhampton Wanderers forward Raul Jimenez was Thursday among 11 Europe-based players named in Mexico's squad for friendlies against the Netherlands and Algeria.
It added that Trovato, who has been president of the Asuncion club since 2014, had 10 days to lodge an appeal.
Icardi opened the scoring for PSG in the ninth minute which was set up by Mbappe after an impressive long dribble. It was the first goal since February for the Argentinean, who recently took over the number nine jersey from the departed Edinson Cavani.
Monchengladbach sporting director Max Eberl called his club's group exciting "as we face Europe's top dogs." Leipzig coach Julian Nagelsmann might face the biggest challenge to repeat his side's semifinal performance last season, with key figures Timo Werner and Patrik Schick having left the club. Enditem
By appointing the crowd favourite Naldo, the club is trying to correct the mistakes made by predecessor David Wagner.
However the CBF rejected the petition, arguing that Flamengo's squad was big enough to field a team for the match.
"It's our 10th straight year at the Sport Show," said Airgoal's Liang Jiahua. "We are bringing some new products here and the sales are satisfactory."