Matthew Schaefer jumped onto the darkened ice at PPG Paints Arena and, along with New York Islanders teammate Max Shabanov, took the traditional solo lap every player makes before their NHL debut.

The 18-year-old became the youngest player in history to record an NHL point in his debut just 12:02 into the Islanders’ opener Thursday night, feeding Jonathan Drouin for the Islanders’ first goal o...