Adrian Peterson left the Vikings to travel to South Dakota this week. (USATSI)

UPDATED: Adrian Peterson's 2-year-old son has died

Vikings running back Adrian Peterson missed practice this week to be in South Dakota for what orginally was vaguely described as a "medical issue involving a young family member."

Now, according to the Pioneer PressPeterson's 2-year-old son is in critical condition in a South Dakota hospital after he was allegedly beaten by the man dating the boy's mother.

Officials told TMZ the suspect is Joseph Patterson, who has been charged with aggravated felony assault and battery of an infant. 

Authorities haven't confirmed that the child is Peterson's son but Nelson Peterson, AP's father, told the Pioneer Press that it is indeed one of his grandsons. 

"All I can say is, we are asking for prayers and for respect for our family as we deal with this tragic situation," Nelson Peterson said.

As mentioned above, police aren't confirming any details. 

“At this point, we're not going to confirm anything," spokesman Sam Clemens said, via the Argus Leader. "Who the father is does not come into play in this investigation, so we’re not going to be releasing any information as far as that goes."

More details via the Leader:

The child was alone in Patterson’s home at Platinum Valley Apartments, where he’d recently moved with his mother. Patterson called 911 to report a choking on Wednesday evening, but Lt. Blaine Larsen of the Sioux Falls Police Department said it became clear at the hospital that the boy’s injuries were not accidental. ...

The child was taken by ambulance to a local hospital, where he remained in critical condition Thursday night, Larsen said. An examination led doctors to suspect that the boy’s injuries were “consistent with abuse” and not accidental, Larsen said.

Patterson has a son with another Sioux Falls, S.D., woman who, according to court records, had asked for protection orders twice, claiming that Patterson had choked and punched her, threatened her with a knife and held her in the bedroom against her will. 

According to the Leader, the assault-on-an-infant charge "involves blows, shaking or causing a child’s head to sustain impact with an object in a manner that causes bleeding or swelling on the brain. The crime is punishable by up to 25 years in prison."

Peterson returned to Eden Prairie, Minn., where he practiced Friday and told the media that he expects to play Sunday against the Panthers, "without a doubt." He also requested that the media not ask questions about his situation.