In the video that showed Jose Mourinho trying to shake the hands of Paul Lambert and Roy Keane before the final whistle had been blown in the English Premier League match between Chelsea and Aston Villa, it was clear Keane did not take too kindly to the Portuguese's decision to finish the post-match handshake a lot earlier than he should have.
And in the press conference to announce his new autobiography, where he has not been too kind to his former Manchester United manager Sir Alex Ferguson, Keane lent into Mourinho for what he thought was a complete lack of respect shown by the Chelsea boss.
"The game was still going on," said Keane. "It's disgraceful. I've seen him doing it to other managers, it is a disgrace.
"You wouldn't do that on a Sunday morning, you would get knocked out."
The former Manchester United midfielder and current assistant coach of Aston Villa and the Republic of Ireland has had a few things to say about his time as a footballer and manager, but the one to receive the most amount of criticism from the Irishman has been Ferguson.
Keane and Ferguson had a major falling out in 2005, which led to the midfielder leaving the club, and the pair, who enjoyed so much success together at Manchester United, have not made up, with, if anything, the feud only escalating.
Asked to respond to Ferguson's comment, made in his own autobiography, on Keane where he said "his tongue is the hardest part of his body," Keane answered in typical Keane fashion.
"I can kick pretty hard," said the 43-year-old. "I think it was a cheap dig.
"He was never critical when we were winning trophies and he was getting his new contracts and his 'Sir'.
"For Alex Ferguson, not just to criticise myself, but other players who were part of a team that brought some good days, is wrong.
"For him to criticise that when you think of what he made out of it -- he made millions of pounds out of it. He got his statues, he's got his stand named after him.
"I said at the time, I wasn't too bothered about myself, but to criticise people who brought him success was just ridiculous."
So, the next obvious question had to be, will Ferguson and Keane ever make up?
"I'm not sure, I'm not sure football is a small world and eventually, you will cross paths with people again," he added.
"Will I ever forgive him? I don't know."
