A Dassel-Cokato high school football player remained hospitalized Saturday after an emergency three-hour operation to relieve swelling in his brain following a collision in a Friday night game.

Luke Nelson, a 16-year-old junior linebacker, was upgraded to serious condition at Hennepin County Medical Center on Saturday, one day after he was injured making a tackle during the home game in Cokato against Orono.

Nelson underwent the operation shortly after midnight, with surgeons removing the right half of his skull to address the swelling and allow his brain to heal, his parents, Greg and Sara Nelson, wrote on his CaringBridge website early Saturday. The Nelsons said their son was on a ventilator and that the next 72 hours were crucial to his recovery.

The teen’s injury wasn’t immediately apparent during the game, and he was on the field for several more plays until he collapsed. By the time he arrived at a Litchfield hospital by ambulance, he was unconscious and having seizures. From there, he was airlifted to HCMC in Minneapolis in critical condition.

By late Saturday, his condition had improved markedly. He was conscious and alert, responding to doctors, nurses and family, and “even cracking a few jokes.”

“Luke is in there. … What a blessing,” his family’s update on CaringBridge read. “He asks many of the same questions, but I am amazed at what he knows and remembers.”

A teammate, Tom Halonen, visited his close friend in the hospital Saturday along with other members of the team. Nelson was asleep during the visit, but Halonen said Nelson awoke after his friends stepped out of the room, answered questions from doctors and parents, and talked about next week’s football game.

“It sounds like he’s the same Luke that I know,” said Halonen, a middle linebacker.

Orono coach Jeff Weiland, who reviewed the game film Saturday, said it didn’t appear that the injury resulted from helmet-to-helmet contact.

“He had a pretty big collision with one of our running backs that buckled him,” Weiland said. “Our running back was high-stepping, and it looked like it was more a thigh to the helmet.”

Halonen, who also watched game film Saturday, said the collision occurred with about four minutes left in the game when Nelson, who is 5-foot-10 and 180 pounds, collided with one of Orono’s larger running backs. On film, he appeared disoriented after the play, Halonen said, but no one noticed at the time. About five plays later, Nelson walked away from the line of scrimmage and began to fall over when a teammate grabbed him. Coaches sprinted onto the field to find him vomiting and descending into seizures.

“A lot of guys go down from cramps, so we thought he was cramping or something small, but as the ambulance started coming out, you could see the look on the ambulance lady’s face and she had a scared look,” Halonen said. “Us guys in the huddle saw that and it was tough to get back on the field after that.”

Dassel-Cokato coach Ryan Weinandt was one of the first to notice Nelson was having difficulty on the field. He yelled at officials to stop the game.

“It sounds like he’s back to being himself a little bit,” Weinandt said. “That brings so much happiness and relief to me.”

Assistant Dassel-Cokato coach Brian Westby said Saturday he was relieved to learn that Nelson’s condition had improved.

“He’s just a great all-around kid, the type of kid you hope your kids are gonna be like, and the type of kid you want as a teammate,” he said.

Dassel-Cokato coaches met with Nelson’s teammates Saturday morning to update them on his condition.

“They’re all obviously very concerned. You tell them this is a part of the game,” Westby said. “Unfortunately things like this can happen in the game of football and in life, too.”