Heart disease led to the collapse last week of a Minnesota high school football player on the field and his subsequent death, authorities announced Monday.

Esko quarterback Jackson Pfister, who would have turned 16 this Saturday, was stricken late in the game Friday at Veterans Field in Aitkin, police said. He was taken by ambulance to Riverwood Healthcare Center in Aitkin and died shortly afterward.

According to the preliminary report from the Ramsey County Medical Examiner’s Office, Pfister’s death was “natural due to congenital heart disease,” Aitkin Police Chief Tim Catlin said in a statement.

Pfister’s mother, Brooke, posted on Facebook that her son had a congenital heart defect and had open-heart surgery several years ago.

Before being cleared to participate in a sport, Minnesota high school athletes must submit a form signed by a health care provider after an exam. It includes questions about whether an athlete has experienced heart-related problems or been told by a doctor that they have heart problems.

Esko Public Schools Superintendent Aaron Fischer said Monday that Pfister was “appropriately approved [medically] to play” football.

Pfister, a late substitute at quarterback during Esko’s 41-14 victory over Aitkin, fell to the ground about 10 yards behind the play, then “got up, began to walk over to the sideline and collapsed,” said Matt Fowler, who was calling the game on Aitkin-based KKIN Radio.

Said Fischer in a statement: “Jackson was a tremendous young man that brought joy to everyone he was around. The entire community is grieving this loss. Our thoughts and prayers go out to his family.”

Fischer added that support services were made available to students and staff Sunday in the school cafeteria, and the support continued Monday.

Esko’s next football game is at its home field Wednesday vs. Crosby-Ironton. Fischer said district officials are working on honoring Pfister in some manner.

Now that a few days have passed for those who knew Pfister to come to grips with his death, “we’ll start thinking about how we want to recognize Jackson and the great individual that he was.”

Services for Pfister are scheduled for 4 p.m. Sunday at Queen of Peace Catholic Church in Cloquet, with visitation starting at 1 p.m.