ORCHARD PARK, N.Y. (AP) &#8212 Kevin Everett sustained a “catastrophic” and life-threatening spinal-cord injury while trying to make a tackle during the Buffalo Bills’ season opener and is unlikely to walk again, the surgeon who operated on him Monday said.

“A best-case scenario is full recovery, but not likely,” orthopedic surgeon Andrew Cappuccino said. “I believe there will be some permanent neurologic deficit.”

Everett was hurt Sunday after he ducked his head while tackling the Denver Broncos’ Domenik Hixon during the second-half kickoff. Everett dropped face-first to the ground after his helmet hit Hixon high on the left shoulder and side of the helmet.

Cappuccino noted the 25-year-old reserve tight end did have touch sensation throughout his body and also showed signs of movement. But he cautioned that Everett’s injury was life-threatening because he was still susceptible to blood clots, infection and breathing failure.

Everett is in the intensive care unit of Buffalo’s Millard Fillmore Gates Hospital, where he is under sedation and breathing through a respirator as doctors wait for the swelling to lessen. Cappuccino said it will take up to three days to determine the severity of the injury and the recovery process.

Cappuccino repaired a break between the third and fourth vertebrae and also alleviated the pressure on the spinal cord.