Already this year, the sisters have cited injuries as their reason for playing only three events.
In 2005, she pulled out of the national championships, citing injury.
Davenport, who turned 30 last month, has not played on tour since March, citing a back injury.
He had refused to play for Germany, citing injury and international retirement.
However, just days before the event, Taylor pulled out of the bout citing an injury.
Before the start of the team challenge, John withdrew from the competition, citing injuries to both legs.
Zhang cited injury and fatigue as the main reason for her loss.
Reyes, who could have provided bullpen insurance, cited a back injury.
However, Agbeko pulled out of the fight just days prior citing an injury.
The ringside doctor put an end to the bout citing an injury.