High school basketball phenom Alijah Arenas, the son of former NBA superstar Gilbert Arenas, was rushed to the hospital with serious injuries after crashing his Tesla Cybertruck early Thursday morning … TMZ Sports has learned.

It’s unclear what caused the wreck, but the luxury vehicle was completely mangled on the side of the road of a Los Angeles neighborhood based on images we have viewed.

We’re told emergency responders raced to the scene at 4:55 AM — after fire personnel responded to a “trapped patient” … but when help arrived, everyone inside the vehicle had already made it out.

Arenas is a five-star recruit who committed to USC earlier this year … and told TMZ Sports just this month he had a sponsorship deal with adidas.

Arenas averaged nearly 31 points, 7.8 rebounds and 2.8 assists throughout his high school career.

Back in November, we spoke with Gilbert and Alijah … and the latter joked his three-time All-Star dad avoided one-on-one matchups due to his polished skills on the court.

Gilbert was slated to appear on his “Gil’s Arena” podcast on Thursday … but the show has since been canceled following the news.