A mixed martial arts fighter pleaded not guilty in Circuit Court to an assault charge involving his estranged wife, UFC mixed martial arts fighter Rachael Ostovich, who has since filed for divorce.

Arnold Berdon III appeared at his arraignment Thursday before Circuit Judge Colette Garibaldi after an Oahu grand jury recently returned an indictment charging him with second-degree assault. His attorney, Myles Breiner, entered a not-guilty plea to the charge.

Garibaldi set his trial for February. Berdon remains free after posting $75,000 bail.

Second-degree assault is a Class C felony punishable by up to five years in prison.

Ostovich filed for divorce Tuesday in Family Court, exactly a month after the alleged assault took place at a home in Makaha. The divorce was filed under her married name, Rachael Ostovich- Berdon. She and Berdon have a daughter together.

Ostovich and her attorneys could not be reached for comment.

After the arraignment, Breiner declined to comment on the assault charge. “I do know Arnold feels great remorse about the dissolution of their marriage,” he said.

He noted Berdon is participating in a domestic violence intervention program that includes anger management classes. “He’s participating in it as we speak,” Breiner said.

The alleged assault occurred during the early morning hours of Nov. 18. In a petition for a temporary restraining order filed at Family Court the day after the assault, Ostovich claimed Berdon repeatedly punched her in the head, face and ribs.

She sustained a fracture to her orbital bone and fled the home through a balcony.

Berdon turned himself in to police Nov. 20.

Ostovich’s manager initially said her Jan. 19 bout with flyweight Paige VanZant was canceled but later said it was back on after Ostovich got a second opinion about her injuries.

Her manager said Ostovich never wanted to withdraw from the UFC fight.

Breiner said, “Both Arnold and his family hope that she is successful in her career. They have no animus or anger toward her or her family.”