Robert Williams III leaves first Celtics start after scary fall

This is not how Robert Williams III wanted his first start with the Celtics to go.

The 2018 first-round pick out of Texas A&M had to leave Saturday's matchup with the Hornets after a scary fall.

On the play in question, Williams attempted to put back a Marcus Smart miss, but lost his balance and fell directly to the floor on his back.

Robert Williams III has left the game after falling on his back vs the Hornets ? (@AAANe_MAnews) #AAANortheast pic.twitter.com/9SIXEnDIGg
— Celtics on NBC Sports Boston (@NBCSCeltics) March 23, 2019

He stayed on the ground for a good amount of time before leaving the game.

The team announced soon after Williams would not be returning.

#NEBHInjuryReport Rob Williams has suffered a lower back contusion and will not return to tonight's game.
— Boston Celtics (@celtics) March 23, 2019

Williams came into the game averaging 2.6 points and 2.2 rebounds in 2018-19.