Officials say Ryne Dougherty, a junior linebacker, suffered a brain hemorrhage.
It happened Monday night in a game against Don Bosco Prep in Ramsey.
Players and coaches say Dougherty made a tackle, then collapsed. He got to his feet, collapsed again and was taken from the field in an ambulance.
Doctors at Hackensack University Medical Center operated to relieve the pressure on his brain.
Dougherty is the third North Jersey football player to suffer a life-threatening injury this season. Players from Cliffside and Waldwick collapsed and died on the field during August.
Information from: The Record of Bergen County, http://www.northjersey.com