I showed great courage to replace Roy Keane at Man United - what happened next was beyond my wildest dreams

When Manchester United make the trip to Tottenham Hotspur in the quarter-finals of the Carabao Cup on Thursday evening, there is very little to split the teams with the bookmakers.

Both sides are members of the Premier League's old 'Big Six' club and both teams have suffered indifferent seasons so far. United dominated English football for two decades and once had the ability to routinely sign Spurs' best players.

Teddy Sheringham swapped White Hart Lane for Old Trafford in 1997 and went on to win the treble with United. Dimitar Berbatov also made the same move to great success.

But perhaps the most successful, if not understated, signing United made from the North London club was their move to bring in midfielder Michael Carrick in the summer of 2006.

United paid £18.6million to bring the 25-year-old to Manchester, as Sir Alex Ferguson looked to reel in Jose Mourinho's Chelsea after they had won the two previous Premier League titles.

But the decision to bring in Carrick hadn't convinced United fans they could do that.

One fan from the Independent Manchester United Supporters' Association told BBC Sport at the time: "I cannot understand what is going on. I have not spoken to anybody who, when £18.6m became available, would have spent that on Michael Carrick.

"But people have questioned Sir Alex Ferguson's judgement in the past and finished up with egg on their face and I hope it happens again."

And boy did the doubters end up with egg on their faces.

Carrick inherited the No.16 shirt which had been worn by United's long-serving captain, Roy Keane. Keane had left the club a few months earlier in abrupt fashion after the fallout from his infamous critical assessment of his United teammates on MUTV.

Ferguson knew he would