The terrifying video of Zac Stacy attacking his ex-GF has the sports world outraged ... with players like NFL star Davante Adams calling for him to rot behind bars.
TMZ Sports broke the story ... Stacy brutalized the mother of his child, punching her in the head before slamming her into a television as their 5-month-old son sat feet away during an incident over the weekend.
The Green Bay Packers receiver reacted to the story in a fiery tweet Thursday ... saying, "ZAC STACY NEED TO BE THROWN UNDER THE JAIL."
"Any man that puts his hands on a woman is a coward," he added. "Can’t believe what I just saw."
Chris Long -- who was Stacy's teammate with the St. Louis Rams -- expressed his disbelief ... saying, "Woke up to the Zac Stacy video. Made my stomach turn."
"Crazy to play w someone for a couple years & you have no idea what kind of bulls**t they do at home."
MMA star Uriah Hall was so upset over the vid, he even hinted at retaliating with violence of his own.
"Looking for a wife beater Zac Stacy anyone seen him?," Hall tweeted. "Looking to give an ass whooping on site !!!"
As for the incident, the woman filed for a restraining order on Monday ... out of fear for her life and the life of their son.