Sunderland boss Roy Keane admits he would have gone to prison had Sepp Blatter's latest demand come into force while he was a player.
FIFA president Blatter wants those who deliberately make dangerous challenges to face legal action.
Most infamous was a knee-high lunge on Alf Inge Haaland during the Manchester derby at Old Trafford in 2001, which Keane later revealed in his autobiography was a pre-meditated revenge attack for a spat that began four years earlier.
Speaking ahead of his side's Premier League game against Everton on Sunday, Keane said: "I have to be careful with this subject. I would have been doing a bit of 'porridge' myself!
"People in the media have been saying some of the tackles have been horrendous.
"I've heard before that if it happened in the street then you might be charged with assault.
"I know there's been one or two court cases over the years. You're opening a can of worms there - I think you'd have to be very careful."
But Keane said: "As bad as that tackle was on Yorkie that day, Yorkie was okay.
"Luckily, Yorkie's not nasty enough to seek revenge I suppose.
"It's very hard to gauge what's going on in the game because the game is that fast now.
"It's trying to gauge what players mean and what's accidental."