The worst thing for any football fan is to see a player they love leave their club behind and join a team that they despise.
Some stars in the Premier League have just done that in recent years and have become hated by the fans that once adored them.
Despite it being seen as the ultimate sin by fans for a player to join one of their rivals,some stars still seem to make these shocking moves.
But which players are seen as the biggest Premier League traitors?
Let's take a look! Here are our top 10: