Bronny James, the eldest son of basketball great LeBron James, is in a stable condition after suffering a cardiac arrest, a spokesperson for the family said.
A statement to ESPN said the 18-year-old was training with the University of Southern California (USC) basketball team when the incident happened.
“Medical staff was able to treat Bronny and take him to the hospital,” it read.
“He is now in stable condition and no longer in ICU (intensive care unit).”
It added: “We ask for respect and privacy for the James family and we will update media when there is more information.
“LeBron and [his wife] Savannah wish to publicly send their deepest thanks and appreciation to the USC medical and athletic staff for their incredible work and dedication to the safety of their athletes.”
NFL star Damar Hamlin, who plays for the Buffalo Bills, tweeted his support for the family.
Hamlin was cleared to return to action in April, four months after suffering a cardiac arrest on the field during an NFL match.
He said: “Prayers to Bronny & The James family as well. Here for you guys just like you have been for me my entire process.”
NBA legend Magic Johnson said “we are praying and hoping he makes a full and speedy recovery”.
When LeBron James signed a two-year contract extension with the Lakers in August 2022, keeping him at the club through the 2024-2025 season, one of the key factors was to extend his career in order to play with or against Bronny.
The eldest of three siblings, Bronny has a younger brother, Bryce Maximus, 16, and sister, Zhuri, eight.
Like his father, he has received widespread attention for his basketball talent, with a video of him hitting a one-handed half-court shot going viral in 2014, shortly before his 10th birthday.
LeBron has been supportive but protective of his son’s basketball career, speaking out against college coaches in 2015 who were already sending him letters and scholarship offers.
In May, Bronny rejected a number of approaches to commit to the University of Southern California following an impressive basketball career at the Sierra Canyon High School in Los Angeles.