Manhattan prosecutors have dropped one of the assault charges against Houston Rockets guard Kevin Porter Jr., acknowledging Monday during Porter's hearing in Manhattan Criminal Court that he did not fracture one of his girlfriend's neck vertebrae during an alleged attack at a New York City hotel last month.

According to the New York Post, Manhattan Assistant District Attorney Mirah Curzer cited "insufficient evidence" as the reason for dropping the charge of second-degree assault, telling Judge Jay Weiner on Monday, "What initially appeared to be a fractured vertebrae was not in fact an injury caused by the defendant."

Porter was arrested after an alleged attack on girlfriend Kysre Gondrezick, a former WNBA player, at the Millennium Hilton near the United Nations on Sept. 11. Prosecutors initially said during Porter's arraignment a day later that the attack left her with a fractured neck vertebra and a deep cut above her right eye.

Porter's defense team shared documents with the Post indicating the presumed neck fracture was actually a congenital defect.

Porter still faces charges of second-degree strangulation and third-degree assault, to which he has pleaded not guilty. According to the Post, Curzer told the judge that her office offered a plea deal on the lower third-degree assault charge but that Porter rejected the offer.

The Rockets have told Porter that he cannot be with the team in any capacity after his arrest. Aside from that, everything else related to Porter and his situation falls under the NBA's collective bargaining agreement and will be handled by the league, Rockets GM Rafael Stone said at the team's media day earlier this month.

Porter's next court appearance is scheduled for Nov. 27.

The Associated Press contributed to this report.