Former Kansas City Chiefs assistant coach Britt Reid pleaded guilty on Monday to felony driving while intoxicated and causing crash in 2021 that severely injured two children.
Reid, 37, said in court that he regretted his actions, which left five-year-old Ariel Young with traumatic brain injury.
She was in a coma for 11 days and in November the Chiefs reached a confidential financial agreement to cover her ongoing medical treatment.
"I made a huge mistake. I apologize to the family. I didn't mean to hurt anyone that night."
Prosecutors reached a plea agreement with Reid to seek a sentence of no more than four years in prison for the charge, which could have seen him face up to seven years behind bars.
Felicia Miller, Ariel's mother, told judge Charles H. McKenzie her family opposed the deal.
"I don't think he should receive it," said Miller, who was joined in the courtroom by six relatives and friends who wore T-shirts with the words "Justice for Ariel" on the front.
Attorney Tom Porto said victims of the crime "are outraged the prosecuting attorney is not seeking the maximum sentence allowable by law."
Monday's hearing in circuit court in Kansas City, Missouri, lasted half an hour.
Reid admitted that he was intoxicated when the truck he was driving on February 4, 2021, hit two vehicles parked on an entrance ramp to a motorway near the Chiefs' practice facility.
Reid, who originally pleaded not guilty, is scheduled to be sentenced on October 28.
The accident occurred three days before the Chiefs played the Tampa Bay Buccaneers in the Super Bowl.
Reid, the son of Chiefs head coach Andy Reid, was the linebackers coach of the NFL team at the time. The team immediately placed him on administrative leave and later allowed his contract to expire.