On Thursday, Ian Begley of ESPN passed along word of the ailment and noted head coach Jeff Hornacek said the ailment is "unrelated" to a knee injury the first-year player dealt with during NBA Summer League.
The Knicks' selection of Ntilikina made sense on draft night since he's a natural fit for the triangle offense, but New York agreed to mutually terminate Phil Jackson's contract less than a week later.
The triangle offense followed Jackson out the door, raising questions about whether Ntilikina was the sensible choice with the eighth overall pick.
Regardless, the 19-year-old Frenchman is a big part of the Knicks' future.
A team never likes to see its first-round pick go down with an injury, but there are no indications Ntilikina's absence will be an extended one with three more preseason games on the schedule.
New York re-signed Ron Baker and added Ramon Sessions in the offseason. The pair provide head coach Jeff Hornacek with enough depth at point guard to get by until Ntilikina is healthy enough to return.