It is fair to say that Jose Mourinho and Pep Guardiola have not exactly been the best of friends in recent years.
With Guardiola's move to Manchester City confirmed months before the end of the season, the stars have seemingly aligned to ensure that Mourinho will take the helm of his new employers' most bitter of rivals, at least according to the BBC among others.
City's rise to the top of English football has noticeably added extra spice to their rivalry with the Red Devils, but next season's Manchester derby is set to have an exciting new dimension.
Mourinho gladly played the role of Guardiola's tormentor in La Liga, guiding his Real Madrid side to a domestic and Champions League title at Barcelona's expense, with plenty of eye-pokes, red cards and angry outbursts from both sides along the way, leading to some of the fieriest El Clasico encounters in living memory.
Guardiola's philosophy of slick possession football has largely depended on instilling an enjoyment of the game into his players, but it is no secret that has never exactly relished the prospect of sharing a touchline with Mourinho.
The intensity of the rivalry was even cited as a key factor in Guardiola's decision to take a sabbatical from management following his departure from the Camp Nou, although he is likely to have learned a number of lessons since then.
Nevertheless, since confirming his arrival at the Etihad, the Spaniard has reportedly kept an eye his rival's next move, with Mourinho's reportedly imminent arrival at Old Trafford carrying an increasing sense of inevitability since his second spell at Chelsea was brought to an end.
Some have even suggested that he was worried by the prospect of meeting his old foe again, although he is by no means the only one to have fallen under a Mourinho-shaped shadow.
Louis van Gaal was barely even halfway through celebrating United's first piece of major silverware since the days of Sir Alex Ferguson before the news broke, although many of the club's fans are unlikely to be shedding too many tears.
A failure to qualify for the Champions League ultimately proved to be a fatal blow to the Dutchman's tenure, which was frequently subjected to fierce criticism from fans and ex-players alike.
Europe's premier competition has also laid down possibly the only black mark on Guardiola's time in Germany, which may well hand a slight psychological advantage to Mourinho, who will be out to prove a point following a disastrous end to his second spell at Stamford Bridge.
With both managers so desperate to make their mark on next season's Premier League, this could be the most fascinating chapter yet in one of football's most high-profile managerial rivalries.