Of course, the topic came up thanks to New England Pats star Chandler Jones ... who says he wants to fight his big bro, UFC champ Jon Jones, in a 1-round charity match.
But Tisch says ... if Jones was one of the G-Men, he'd shut those plans down in a New York minute.
"I think the risk is too high," Tisch says ... "That wouldn't make me happy."
In fact, Tisch says he's always worried that when his players engage in off-the-field activities, he fears Murphy's Law ... that whatever can go wrong, will go wrong.
Translation -- don't plan on seeing Victor Cruz go skydiving anytime soon.
Tisch compares fighting to another ... maybe more dangerous activity ... and says if star WR Victor Cruz wanted to do this ... "that wouldn't make me happy."