Steve McClaren has opened up on the 'toughest five months' of his life during his start to life at Manchester United and revealed how Roy Keane erupted at the former England manager.

McClaren was brought in as Sir Alex Ferguson's assistant in January 1999 and had just enjoyed a 2-0 win over Inter Milan in the build-up to winning the Champions League trophy later that year.

However, McClaren reveals how his praise after a not-so-great team performance came back to bite him when United hard-man Keane wasn't impressed with the remarks.

Steve McClaren talks about his 'tough' start to life as Sir Alex Ferguson's No 2 at Old Trafford

McClaren also opens up on the time Roy Keane demanded the truth over a team's performance

'I think it was against Inter Milan at Old Trafford and I think they won 1-0', McClaren said during talkSPORT's documentary on United's treble winning season. 'It wasn’t a good performance and I think I came in and was a bit over the top by saying “well done boys, great win”.

'Roy Keane just turned round and said: “Steven, don’t give us that bulls***,” he said. “Don’t give us that c***. When we’re c***, tell us we’re c***”.'

McClaren arrived at the club after enjoying a successful period with the Rams that saw them win promotion to the Premier League in 1996, as he worked alongside Jim Smith as his assistant.

United had just beaten Inter Milan 2-0 but Keane wasn't happy with how the team had played

'Don’t give us that c***. When we’re c***, tell us we’re c***,' Keane snapped at McClaren

The 58-year-old revealed that it was between him and David Moyes to become Ferguson's No 2, but he would eventually get the nod.

'I do know there were a few people in the frame and it was David Moyes and myself at the top of the charts,' McClaren said. 'I don’t know why – you’ll have to ask him why he picked me.

'But I remember the first day I joined and the first day of training especially and I remember going in the office and kind of saying, “what do you want me to do?”

'We had just won 8-1 on Saturday, you know, what do you want me to do? And he (Ferguson) said, “Look son, what did you used to do at Derby?” And before I had even got an answer out he said: “Whatever you did at Derby, that’s why you’re here.”'

McClaren was brought in as Ferguson's assistant in 1999 after a successful spell at Derby

United went on to win the famous treble during McClaren's first five months at the club

McClaren also admitted that his first five months at Old Trafford were the toughest of his life and that he felt a bit lost to begin with.

'The first five months, from January up until the end of May, were the toughest five months of my life, in whatever I’ve done.

'Nothing prepared me for them first five months. The environment was tough, the players were tough. If a cone was out of place, a decision was wrong, they let you know. They wanted the best.'