The fickle nature of football means that supporters, providing that the best performances are being produced on the pitch, will forgive most misdemeanors.
However, what is rarely forgiven is a scenario in which a player leaves his current club to link up with their bitterest of rivals. In some circumstances, the move doesn't even have to go through. In 2011, Wayne Rooney was heavily linked with Manchester City, but he eventually extended his contract with Manchester United. Even so, some United fans still harbour misgivings towards the striker.
The England international had become one of the key members of the squad at Goodison Park since his arrival from Middlesbrough in 1995, but with his contract due to expire the following summer, he'd informed manager Walter Smith of his desire to join the red half of Merseyside.
A despondent Smith said at the time: "Following discussions between myself, Bill Kenwright, the player and his agent, Nick Barmby has indicated his desire to leave Everton. Obviously with a year of his contract to go this leaves the club in an awkward position. We have made every attempt to retain the player's services, but after a number of meetings the player eventually indicated that he would like to leave the club.
"The player has indicated to me that the club he would like to move to is Liverpool, a club who have already made enquiries about the availability of the player. Now that discussions between Everton and Nick have fallen through we must wait for an approach from Liverpool to see where we go from here.
"From the club's point of view we have placed Nick on the transfer list with immediate effect due to the fact that although he wishes to join Liverpool there is always the possibility that we might not reach agreement with that club."
An agreement was eventually reached between the two neighbours, with Liverpool paying out £6m after their initial bid of £3.5m was rejected. Consequently, Barmby had become the first player to move from Everton to Liverpool since Dave Hickson in 1959, while it was the first business concluded between the two clubs since Gary Ablett signed for The Toffees in 1992.
Barmby's first season at Anfield was a successful one as he played a part in helping the club to win the FA Cup, League Cup and UEFA Cup, while he scored with a header within 12 minutes of the home Merseyside derby, much to the disgruntlement of the travelling support.
His second campaign was blighted by injuries, though, and in the summer of 2002 he was sold to Leeds United. He failed to establish himself at Elland Road and after a brief loan stint with Nottingham Forest, in 2004 Barmby joined his hometown club Hull City, where he would go on to spend the remaining eight years of his playing career.