EDEN PRAIRIE, Minn. — Authorities say a 2-year-old has died of injuries suffered in an alleged child abuse case in South Dakota, and a person with knowledge of the situation tells The Associated Press the boy is the son of Minnesota Vikings running back Adrian Peterson.

Peterson said he is certain he will play Sunday, despite missing practice earlier this week.

Peterson declined to speak Friday specifically about the situation, asking reporters to respect his and his family’s privacy. His father, Nelson Peterson, told the St. Paul Pioneer Press and the Star Tribune of Minneapolis that one of Peterson’s sons was in critical condition at a hospital in South Dakota.

Lincoln County State’s Attorney Tom Wollman confirmed the death of the child Friday. He had been in critical condition in a hospital with severe head injuries since Wednesday.

The man accused in the case, Joseph Patterson, 27, is charged in Lincoln County with aggravated assault and aggravated battery on an infant. He had a court appearance Friday and was ordered held on $750,000 cash bond.

Peterson is second in the NFL with 421 yards rushing and first in the league with five touchdowns.

“Football is something I will always fall back on,” Peterson said. “It gets me through tough times.”