A Dassel-Cokato High School junior who suffered a head injury during a football game on Friday night was still in serious condition Sunday, but was well enough to joke with his mother about running up her medical bills.

Sara Nelson said that her 16-year-old son’s prognosis is unclear but that the doctors will know more after further tests on Monday.

Luke Nelson was hit in the head, possibly by the thigh of a larger Orono player he was trying to tackle. He was airlifted in critical condition to Hennepin County Medical Center Friday night. Doctors removed half of his skull to reduce pressure on his brain. He was fitted Sunday with a helmet to protect him until the skull piece is replaced, his mother said.

At a news conference Sunday afternoon outside the medical center, Sara Nelson said the family is realizing that Luke might not play again with his high school team.

His father, Greg Nelson, said his son is not just a three-season athlete, but a “student of the game” who will find a way to be part of his school teams.

Luke Nelson’s apparent concussion is not the Dassel family’s first such sports injury. His parents said Luke had a concussion in ninth grade during football practice, sat out sports for a year and then played in 10th grade with no incidents.

His brother, Isaac, 19, said he suffered a concussion playing baseball at the University of Wisconsin-Eau Claire. He was running after a fly ball from left field and collided with the shortstop. He said he can’t play baseball any more.

“It is one thing for me to get hurt, but to see my little brother go through this, it’s not fun,” Isaac Nelson said.

Sara Nelson said she had some qualms about Luke returning to football, especially with the national attention on sports concussions.

Of Friday’s incident, she said, “This is not intentional. This is a football hit.”

Greg Nelson said he is changing his former “tough it out” attitude toward sports injuries. He said he now would tell players: “If your head hurts, admit it. There is a whole lot more to life than just winning that game Saturday night.” Before Luke’s injury, he said, “I was not willing to go that route.”

Sara Nelson said that Luke tires easily and that he doesn’t remember getting hit.

“It is a blessing to be here” at the hospital, she said, her voice breaking as she added that the surgeons “saved his life.” The family said that their pastor and friends have bombarded them with good wishes and that the Orono football coach sent prayers for a speedy recovery on Luke’s CaringBridge website. “We are so thankful for the support, [some from] people we don’t even know,” Sara Nelson said.

She said Luke was to begin occupational and physical therapies today.

She said his dry humor is evident as he recovers: He charmed a nurse by saying — as he lay hooked to medical lines in his emergency bed — that she didn’t need to get him a Popsicle because he’d go get one himself.

Still quick with the one-liners, Luke had also quipped: “Mom, I think I’m going to max out your [insurance] deductible.”