Nicholas Layman faces charges of attempted murder, aggravated assault and assault with a weapon.
The 19-year-old man was sent for a psychiatric assessment last week after the stabbing at the Topsail Soccer Field and Clubhouse in Conception Bay South, near St. John's.
The boy underwent surgery and was later listed in serious but stable condition in hospital.
Provincial court in St. John's heard Friday that Layman's psychiatric assessment at the Waterford Hospital is being extended at the request of his doctor.
The case is due back in court Oct. 31.