Two-time Grand Slam mixed doubles champion Justin Gimelstob has pleaded not guilty to a charge of battery causing serious bodily injury in a Los Angeles court.
Gimelstob, 41, partnered Venus Williams to win the Australian and French Opens in 1998 and twice reached the men's doubles quarter-finals at Wimbledon.
The American will return to court on 31 January to face trial.
He could be sentenced to four years in prison if convicted.
Since retiring from playing, Gimelstob has worked as a coach and TV commentator and is also a player representative on the ATP Board.