The forward fractured his ankle and leg in the first quarter of the game after going for an alley-oop.
The injury shook up players, coaches and the entire arena as people watched in silence and others prayed.
Hayward was carted off the court on a stretcher and gave a thumbs up.
Outrage soon stirred on social media after a tweet by Fox Sports TV personality Skip Bayless.
Minutes after Gordon Hayward went down with a leg injury, one-half of the sports show Undisputed tweeted about LeBron James and his legacy.
If Gordon Hayward is gone, maybe for the season, LeBron's path to losing a sixth finals gets even easier.— Skip Bayless (@RealSkipBayless) October 18, 2017
In full disclosure, Bayless' first tweet was about Hayward's injury.
JUST AWFUL: First quarter of first game as a Celtic, Gordon Hayward falls awkwardly on alley-oop, looks like badly hurts knee.— Skip Bayless (@RealSkipBayless) October 18, 2017
The outrage began with Toronto guard DeMar DeRozan, followed by Rudy Gay, who called him a "clown" for the tweet.
Really? You are a heartless Clown. Go paint your face! https://t.co/1HYNPwdw7T— Rudy Gay (@RudyGay) October 18, 2017
Others criticized Bayless for having a "sick obsession" with James.
He has a sick obsession with criticizing LeBron. Like he’s jealous or something— Austin (@AustinCTweets) October 18, 2017
ESPN reported Hayward is expected to undergo MRI and CT exams Wednesday.
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