Griner and two of her teammates were walking from the practice arena to the team bus when a man appeared with a knife, sources told espnW's Kate Fagan.
The assailant began yelling, swinging the knife wildly, and chased Griner and the two teammates onto the bus, sources said. During this, the man stabbed at Griner and caught her on the elbow, slightly nicking her.
Agent Lindsay Kagawa Colas said the 6-foot-8 Griner was wearing a winter coat and that the knife barely cut her skin. Griner didn't require stitches.
Griner took to Instagram on Tuesday to say she's doing fine.
The agent said the man also stabbed at one of Griner's teammates but that she was wearing two jackets and the knife didn't go through.
Sources told Fagan that the group of players was trapped on the bus for approximately five minutes before the man apparently voluntarily exited the vehicle.
Colas said the man left the scene, then returned covered in blood and was apprehended by Chinese authorities. She added that the team, the Beijing Great Wall, will review its security protocol after the incident.
Griner said she felt fortunate to be OK.
"I was thinking I was going to end up stabbed in China and if he got to us at the back of the bus, I was going to have to fight this man with a knife," Griner said in an email to the AP.
"The guy was clearly either mentally ill or very drunk," she added. "He was yelling about us hitting his wife and it was pretty clear he had no idea who we were."
A report on the website of local newspaper Liaoshen Evening said the man was drunk but had few other details.
Despite the incident, Griner said she still feels safe in China.
"The game the next day had more security than I had ever seen," she told the AP. "There were three to four cops at every entrance. They were everywhere and the team said they were going to make sure and add more security now too."
Griner plays in the WNBA with the Phoenix Mercury and helped the team win the championship this past September. She led the league with a record 129 blocks and was the WNBA defensive player of the year.
"We are thankful Brittney and her teammates are all okay after this incident," the Mercury tweeted from their team account.
This is Griner's second season in China and first with the Beijing Great Wall. The team was preparing for a road game against Liaoning Hengye. Griner had 19 points, 11 rebounds and six blocks in a win.
Griner, who led Baylor to a 40-0 season and the 2012 NCAA title, was the No. 1 pick by the Mercury in the 2013 draft. She also led the U.S. to a gold medal last month at the FIBA world championship.
Information from espnW's Kate Fagan and The Associated Press was used in this report.
Griner Attacked With Knife
WNBA star Brittney Griner was cut by a knife-wielding man in China but didn't need stitches after the attack.
Nine for IX Shorts - Brittney Griner: Lifesize
Following Brittney Griner's inaugural season with the Zhejiang Golden Bulls, this film chronicles not only her transformation from amateur to professional but also from a celebrated kid with unlimited potential to a mature, self-reliant adult.
The Inside Scoop On Griner
Phoenix Mercury center Brittney Griner discusses her plans to marry fellow WNBA player Glory Johnson, attaining gold at the World Championships in Turkey and winning the WNBA Finals.
Griner: I Am Able To Be Who I Am
Brittney Griner, Kate Fagan, Nefertiti Walker, Lindsay Kagawa Colas talk about breaking down barriers in women's sports.