The family of Luke Schemm confirmed on Wednesday he was taken off life support at a hospital in Denver after being declared brain-dead.
The principal of Luke's school did not know why the football player had collapsed during the game.
Game officials did not see him sustain neck or head injuries while playing.
His teammates are likely to still play in a game on Saturday, something those who knew Luke say he would have wanted.
"Luke gave his all on the field," said Gary Musselman of the Kansas State High School Activities Association. "He lived his life with a passion, and that's what we want them to do."
Luke's death, if ruled to be football-related, would be the third of its kind in Kansas in 17 years.
"Any death is one death too many. We are just heartsick any time a youngster prematurely passes because of whatever reason," said Mr Musselman.
There have been 11 high school football deaths in the US since July, according to the National Center for Catastrophic Sport Injury Research, seven of which were directly related to football trauma.
A 17-year-old high school football player from Kansas has collapsed on the sidelines and died after scoring for his team during a game.