Keane is currently Republic of Ireland assistant coach and a row with Harry Arter has seen the Cardiff City frozen out of this week's squad.
Cascarino told talkSPORT: “I'm not sticking pins in Roy Keane, but his role is a number two. He's probably the most famous number two in world football… but he is noted for his outbreaks against certain people.
“He goes to press conference and talks to the press and journalists laugh at some of the great lines he always comes out with, but his relationship with the players…
“He doesn't like people very much, I have always said Roy doesn't have much time for people – he doesn't.
“And history is there between players, managers, chairmen, directors, there's always something going on with Roy.
“Roy was asked to give an apology to those three players at that particular time, especially McGeady because he let rip into him.
“This is becoming too regular with Roy."