Both the 76ers and the agent for guard Nick Young, Chicago-based Mark Bartlestein, declined to comment on allegations in a civil suit filed in Los Angeles that the player raped a woman almost two years ago.
Young could not be reached for comment.
However, a source closed to Young labeled the claims by a woman referred to in the suit as "Jane Doe" as "preposterous."
"This is just the world we live in today," said the source. "This is the world in 2013."
According to another source, the Sixers and the rest of the NBA were aware of the alleged incident before the Sixers signed Young, 27, to a one-year, $6 million deal.
An unrestricted free agent this summer, Young faces no criminal charges.
The lawsuit, filed in Los Angeles Superior Court, contends that Young, who at the time played for the Washington Wizards, gave the woman gamma hydroxybutyrate, commonly known as GHB or the date-rape drug, and later had nonconsensual sex with her.
The suit contends that Young met the woman and a friend for a drink at West Hollywood's Crown Bar on Aug. 12, 2011. Young approached them with drinks.
Young met the woman who made the allegations on two previous occasions. The next morning, the plaintiff contends, she woke up naked and in bed with Young in his apartment.
When she asked Young why she was naked and in his bed, according to the complaint, Young said they had started having sex but stopped when she passed out. When she asked Young to take her home, he complied.
Ensuing tests later confirmed that the woman had been given GHB, according to the suit, which also says that she underwent exams at the UCLA Santa Monica Rape Treatment Center, which revealed anal and rectal bleeding.
The suit says that the woman has undergone psychiatric evaluations and treatment.
In 59 games with the Sixers this season, including 17 starts, Young averaged 10.6 points and 2.2 rebounds.