Between 1999 and 2001, Bill Beswick was a consultant sports psychologist at Man Utd.
Alex Ferguson apparently hired Beswick on the spot after asking how he could keep his team at the top of the Premier League. 'Train, play and behave like you're number two,' replied Beswick. Beswick would also go onto work with England, Derby, Middlesbrough and Sunderland.
Roy Keane counted himself as a fan of Beswick's work at Man Utd and vice versa.
In a video on Keep It On The Deck, Beswick recounts his first day at Man Utd training. Standing on the sideline during a training game, Beswick witnessed the 'warrior' mentality of Keane.
Even his fellow Corkman Denis 'the most reliable man in football' Irwin was not immune from Keane's ire.
The first day I went to Manchester United, I was watching eight versus eight possession.
Roy Keane - who's a warrior, not just an athlete, not just a competitor but a warrior, the mindset of a warrior - his team have got possession.
Denis Irwin has got the ball. He's looking up, he's trapped, he's going to lose the ball. Roy Keane makes a beautiful run and signals 'Denis!' where he wants the ball. Denis doesn't see him, doesn't hear him, doesn't respond and loses the ball.
Roy Keane ran 40 yards to challenge his teammate: 'Get your head up.' I was shocked.
I was stood next to Alex Ferguson, the manager of Manchester United. He said son, 'Now you know why we win on a Saturday. We win on a Saturday because we have the mindset to train every day.
Picture credit: Sportsfile