Former NBA star and Hawks player Mookie Blaylock’s condition was upgraded from critical to serious Saturday, a day after he was involved in a head-on collision in Clayton County that left a woman dead.

Blaylock, 46, was driving a Cadillac Escalade northbound on Tara Boulevard when for unknown reasons, he crossed over the median and into a southbound lane around 1 p.m., Jonesboro police Chief Franklin Allen told The Atlanta Journal-Constitution.

Blaylock’s vehicle struck another vehicle head-on, injuring two people, Frankie and Monica Murphy, and himself, Allen said.

All three were transported to Atlanta Medical Center, where Blaylock was flown and was on life support and unresponsive Friday afternoon, Allen said. Monica Murphy, 40, died Friday evening at the hospital, Allen said.

Blaylock’s condition improved late Friday and he was removed from life support, but he remained in guarded, but critical condition, Allen said. Late Saturday morning, a hospital spokesman said the former Hawks player was in serious condition.

Blaylock has been under treatment for seizures, a family member told police. It was not immediately known if that contributed to the wreck.

Monica Murphy was a passenger in the second vehicle and underwent surgery, Allen said. Frankie Murphy’s injuries were not serious, according to police.

Jonesboro officers were at the hospital Friday evening with the victims, while other officers remained at the crash scene, Allen said. Allen asked for a Georgia State Patrol reconstruction team to assist with the investigation.

According to Allen, Blaylock had an outstanding warrant out of Spalding County on DUI and drug charges for failing to appear in court. Investigators do not believe alcohol was a factor in the Friday wreck.

Blaylock, a point guard, played 13 seasons in the NBA, including with the Atlanta Hawks from 1992 to 1999. A two-time, first-team pick to the NBA’s All-Defensive Team, Blaylock finished with career averages of 13.5 points, 4.1 rebounds, 6.7 assists and 2.3 steals per game and appeared in the 1994 All-Star game.

The Hawks traded Blaylock in summer 1999 in a three-player deal that allowed Atlanta to later draft Jason Terry with the 10th overall pick. It was a move that caught Blaylock by surprise, he previously said.

“It was very shocking,” he said in an interview at the time, “especially when you’re with a team that long and you think you’re one of the guys that’s going to be around and you’re going to end your career there. But that’s part of the business. I know that’s how it goes.”

Address records show Blaylock, whose real name is Daron, lives in Zebulon in Pike County. The Texas native played college basketball at the University of Oklahoma.

Blaylock is the father of two former standout high school football players at Walton High School in Cobb County. Twins Daron and Zack Blaylock are both safeties at the University of Kentucky. Both were members of Walton’s state runner-up team in 2011.

“We are saddened to hear of the accident today involving Mookie Blaylock and the Murphy family and the ensuing passing of Monica Murphy,” the Hawks organization said in statement released to The AJC late Friday. “Our thoughts and prayers are with the families of all involved.”

Staff writer Mike Morris contributed to this article.