Watch the terrifying moment NBA star Bismack Biyombo appears to COLLAPSE during timeout... leaving Thunder teammates rushing to his aid

Oklahoma City Thunder center Bismack Biyombo appeared to collapse at the side of the court in scary scenes on Wednesday night. 

The terrifying incident occurred during the second quarter of the team's road game against the Portland Trail Blazers, as the players left the court for a timeout.

Biyombo was in a line of Thunder players congratulating their teammates coming off, when all of a sudden he appeared to fall backwards.

The rest of the players and coaching staff immediately looked shocked as he fell back into the chairs at the side of the court, where he received immediate medical attention.

There was a lengthy delay to the game, but it was reported that Biyombo quickly regained consciousness and was alert as medical staff spoke to him.

Bismack Biyombo (in blue jacket) was standing at the side of the court during a timeout

Suddenly, he started to fall back, much to the shock of his fellow players and team coaches

There was immediate shock, as medical staff rushed to the aid of the 31-year-old center

A wheelchair was brought to courtside but he was then seen walking back to the locker room under his own power.

Biyombo, a 13-year NBA veteran, was playing just his fifth game with the Thunder after signing with the team on February 10. 

He has previously spent time with the Toronto Raptors, Charlotte Hornets, Phoenix Suns and Memphis Grizzlies.

Biyombo was able to walk back to the locker room after, albeit appearing to hold his head

Biyombo is pictured warming up before the game in Portland on Wednesday night

Speaking after the game, Thunder coach Mark Daigneault confirmed that the center had been medically cleared, telling reporters: 'He's fine. He just fainted, basically.

'He was in the locker room at halftime laughing and joking.'

Bally Sports Oklahoma sideline reporter Nick Gallo also reported that Biyombo would be subject to further monitoring and evaluation on Thursday, to determine when it will be safe for him to return to the court. 

Oklahoma City play again on Friday night against the Miami Heat.