Roy Keane summed up in story about revenge on terrified Celtic defender in training

Roy Keane joined Celtic with a certain reputation.

11 red cards for Manchester United and innumerable run-ins with teammates and opponents resulted in a certain air of menace accompanying the legendary midfielder wherever he went. More than any player in history, Keane stood up for what he believed in and never met a tackle that he didn't love so it was understandable that some of the more timid players feared the Irishman. One such player was Mark Wilson, the former Celtic defender who really, really did not want to piss off the temperamental midfielder. Darren O'Dea tells a fantastic story about how Keane had it in for Wilson and, despite assuring him that it was acceptable to go in hard in challenges, Keane wasted no time whatsoever in getting his retribution on the Scot. "Mark Wilson was one, you know what he's like... quiet as a mouse but, for some reason, Keano had it in for Wilson," O'Dea told Open Goal. https://twitter.com/opengoalsport/status/872439955984969729 "I think it was one of the first training sessions and as Keano got the ball, Mark Wilson sprinted in to press him but when he went to put the brakes on, he slipped and absolutely cleaned him out. "He obviously panicked, saying 'I'm sp sorry!' and Keano's like 'It's not a problem, mate. Don't worry about it.' "Five minutes later, Willo got the ball, passed it and ten minutes after, Keano hit him like an absolute train and put him up in the air." The moral of that story is that you shouldn't attempt to tackle Roy Keane unless you're prepared for a world of hurt in return.