Boston Celtics small forward Gordon Hayward suffered a devastating leg injury with 6:45 left in the first quarter of opening night vs. the Cleveland Cavaliers.

Fair warning, the video is very gruesome.

The injury is obviously extremely serious and Hayward may very well be out for the remainder of the season.

All players from both teams stopped for an extended period of time for Hayward to be taken care of on the court. This is the type of injury that absolutely no player or fan wants to see in anyone.

The injury is reminiscent of the one Paul George suffered back with Team USA in 2014. That was shortly before the start of the next season and George miraculously did make a comeback late in the following season.

Hayward was acquired by the Celtics in the offseason via a trade with the Utah Jazz. Expectations and excitement surround the Celtics were huge this season with Hayward joining another new addition in Kyrie Irving and also playing for his former college coach at Butler, Brad Stevens.

Hayward will have a long recovery road ahead for him and this also changes a lot of things for the Celtics this season. It's a good reminder of how quickly things can change in this league.

UPDATE: Gordon Hayward has officially been diagnosed with a fractured left ankle.