The associate head coach, who runs New York's offense, will miss an undisclosed stretch of games including Tuesday night against the Pistons.
The Knicks will be without one of their key coaches for a while. Associate head coach Chris Jent, who oversees the offense under Mike Brown, is away from the team for an undisclosed period due to personal reasons, with the situation described as fluid.
Jent already sat out the second and third games of the season, losses to the Celtics in Boston and the Magic at Madison Square Garden. He will also miss Tuesday night's game against the Pistons at MSG.
Assistant T.J. Saint has stepped into Jent's spot on the bench during his absences, leading huddles during timeouts with a clipboard in hand. Saint previously ran the Knicks' Summer League team.
There is no timetable yet for Jent's return.