(CNN) -- Rutgers quarterback Philip Nelson has been arrested and charged on suspicion of assault in southern Minnesota, authorities said Monday.
He is suspected of attacking Isaac Kolstad, 24, a former linebacker at Minnesota State University. Kolstad is in critical condition, his family said.
Nelson, 20, faces one count of first-degree assault and one count of third-degree assault, said Patrick McDermott, assistant Blue Earth County attorney.
He was taken into custody early Sunday morning, according to a statement from Mankato, Minnesota, police.
Officers found Kolstad near a downtown intersection. He was transported by ambulance to a local hospital.
A Rutgers spokesman declined to comment on the case.
"We are in the process of gathering information on the situation and reserve comment until the legal process is complete," said Jason Baum.
Nelson is a recent transfer to Rutgers. A native of Mankato, Minnesota, he played at the University of Minnesota, according to Rutgers' website.
Kolstad graduated from Minnesota State University in December.
He suffered a severe head injury, according to a statement from his family.
"He is currently in critical condition and fighting for his life. He is young and strong, but the battle he has in front of him is enormous," it read.
"We do know that his brain did sustain permanent damage. We do not yet know to what extent and won't for many days. He is very sick. Please pray for Isaac and all of those involved."
Kolstad was being treated at Mayo Clinic Health System in Mankato. A spokesman from there read reporters another statement Monday, on behalf of the victim's family.
"Please keep in mind that behind the headlines, behind the police report and medical data, is a strong, caring man -- a man with an incredible faith in God, a loving husband, a father of two daughters, a son, a brother, a teammate and a friend," it read.
Police have said they are looking for another person believed to have been involved in the assault.
That suspect was identified as a white male in his early 20s. He was wearing jeans and a red T-shirt that was torn during the incident.
Authorities released surveillance video and stills, showing a large number of people in the area of the assault, and are asking anyone with information to step forward.
"In order to ensure that justice is served, we need the public's help," said Todd Miller, Mankato's director of public safety.
CNN's Kara Devlin contributed to this report.