HONOLULU (AP) — Olympic silver medalist and former University of Hawaii All-America volleyball player Kim Willoughby pleaded not guilty Monday to a charge of first-degree assault.

Circuit Judge Derrick Chan scheduled a trial for May.

Willoughby, 27, remains free after posting $50,000 bail.

A grand jury indicted Willoughby in September 2007 in connection with an incident outside the Pipeline Cafe in Honolulu on Dec. 16, 2006.

She is accused of intentionally or knowingly causing serious bodily injury to Sara Daniel, according to the indictment that was held under seal until Willoughby turned herself in last week.

Jim Fulton of the city prosecutor's office said he could not disclose details of the case aside from the fact that the indictment stemmed from an altercation.

Fulton said Willoughby learned of the indictment while she was outside the country, contacted an attorney and agreed to surrender to authorities. In return, extradition wasn't sought, he said.

Willoughby's attorney, Richard Hoke, didn't immediately return a call seeking comment.

Willoughby, who plays volleyball professionally in Italy, was a member of the U.S. women's volleyball team that lost to Brazil in the finals in Beijing.

In 2001, Willoughby was charged in a domestic abuse case and eventually entered deferred guilty pleas to one count of abuse of a household member and one count of third-degree assault, both misdemeanors.