Boston Celtics forward Gordon Hayward suffered a horrific leg injury in Tuesday night's season opener against the Cleveland Cavaliers.

Hayward's left leg bent awkwardly after he went up for an alley-oop pass, collided with LeBron James and collapsed under the basket with 6 minutes, 45 seconds left in the first quarter.

After the game, Boston coach Brad Stevens said Hayward dislocated his ankle and fractured his tibia, while the Celtics later announced that Hayward has a fractured left ankle.

The 27-year old Hayward was playing in his first-career game with the Celtics, after signing a 4-year, $128 million free agent deal during the offseason.

A 2017 NBA All-Star, Hayward played the first seven years of his career with the Utah Jazz.

We certainly wish the best for Hayward, and hope he has as speedy of a return as possible.

The video of the injury is below, but be warned; it is not for the squeamish: