Ex-NBA star Roy Hibbert is a big video gamer and was clearly upset about the tragedy at the Madden tournament in Florida ... but tells TMZ Sports don't blame violent video games, GUNS are the real issue.
"The conversation shouldn't be on video games," Hibbert says ... "It should be on the other thing. And you know what the other thing is."
24-year-old David Katz opened fire at the "Madden '19 NFL" tourney in Jacksonville -- killing 2 people and injuring 11 before turning the gun on himself.
Katz was reportedly furious after losing in the tournament earlier that day.