Steven Adams has once again stunned fans and commentators after shrugging off a "fastball to the head" during the Memphis Grizzlies' first game of the NBA season.

The Kiwi centre helped the Grizzlies claim a thrilling 115-112 overtime victory over the Knicks, but one of his most notable highlights from the game came when he wasn't even on the court.

Midway through the fourth quarter, Adams – who was walking from the bench to get ready to return to the game – was smacked in the head by an errant pass from future Hall of Famer and youngest ever MVP, Derrick Rose.

The pass, which came at full force, would've probably knocked over anyone else, but not Adams, who took it like a champ and simply laughed it off.

Steven Adams remains unbreakable. Photo / Getty

His reaction shocked ESPN commentators.

"How does that not knock you out? That was a fastball to the head," Jeff Van Gundy said.

"Most people would be down on the ground writhing in pain," Breen added, joking that "the ball has a dent in it".

Video of the incident was also shared by NBA legend Shaquille O'Neal's 'Shaqtin' a Fool' account on Twitter, where he celebrates the funny side of the sport.

Adams finished the game with three points, 14 rebounds and three assists in 33 minutes, with his teammate Ja Morant leading the way with 34 points to help the Grizzlies start their season with a win.