Not since 1987 has a former Manchester City player worn the famous red of Manchester United.
However, during the last 30 years no fewer than nine ex-United players have defected to the blue half of the city.
For the vast majority of these three decades, United have been massively superior to City and, with the exception of Carlos Tevez, most transfers have felt a bit like a younger sibling being handed down some of his big brother’s used clothes.
But City and United are equals now. Their rivalry is more intense than ever, so a move between the clubs at this stage would be highly controversial.
Cue the king of controversy, Jose Mourinho, who is eyeing a summer move for City goalkeeper Joe Hart, according to The Telegraph.
Per The Telegraph, Mourinho could move for Hart if United lose no.1 stopper David de Gea to Real Madrid.
Hart is a fan favourite among the City faithful, but his manager is less enamoured and the 30-year-old appears to be surplus to requirements at the Etihad Stadium.
Is is therefore hard to know exactly how this unlikely transfer would go down in Manchester.
United fans would no doubt try to claim bragging rights at pinching one of City’s big names.
City supporters could in turn mock United for feeding off their scraps.
Realistically though, such a transfer seems nothing more than fantasy at this stage.
Even if United were to lose De Gea, there is no guarantee that City would be willing to do business with their arch rivals.
West Ham is a more likely destination for Hart, suggest The Telegraph, with the Hammers probably taking the England international on a season-long loan.