Much has been made of Jose Mourinho's return to the helm at Chelsea, and many are predicting a repeat of the success which saw the West London club win five trophies, including two Premier League titles, during the Portuguese's three-year tenure.
However, in my opinion the 50-year-old is currently the most overrated boss in the game. Whilst his man-management skills are indisputably top-class and his matchday tactics are as astute as any other manager's, his controversial personality and the unsustainable running of the club he takes charge of make him unworthy of the claim put forward by many that he is the best manager in the world, or even close.
Firstly, Mourinho's tendency to destroy his relationships with players is a time-bomb for instability at a club. His reported fall-outs with Real Madrid captain Iker Casillas, as well as stars Cristiano Ronaldo, Sergio Ramos, Pepe, Alvaro Arbeloa and Jose Callejon when he was manager there for three years were a key reason for Real's disappointing performance in Spain's La Liga last season due to the total lack of squad harmony.
His controversial media appearances, from announcing himself as the 'Special One' in his first press conference as Chelsea manager in 2004, to claiming he had never heard of Barcelona assistant manager Tito Vilanova (whom he also insulted in Spanish in the same sentence, after having famously gouged his eye in the 2011 Spanish Supercopa final), to saying that "maybe Pep [Guardiola] has a restaurant in Oslo" after Barcelona's controversial victory over Chelsea in 2009, refereed by Norwegian Tom Henning Ovrebo, also bring unwanted attention to every aspect of the club Mourinho is in charge of, creating more pressure for them to do well and therefore adding to the recipe for disaster.
In addition, on the financial side of things, even Mourinho's wages are a drain on his club. He is reportedly making just over £12 million per year at Chelsea, amounting to around £50 million over four years, the same much-criticicised amount Chelsea paid for Spanish flop Fernando Torres.
To put Mourinho's wages into context, one of the players most often cited as an example of footballers earning too much, Zlatan Ibrahimovic, earns a little under an annual £11.5 million; why then, should the same logic not be applied to Chelsea's new manager?
On a similar theme, Mourinho's team-building strategy is hugely expensive: essentially he prefers to buy ready-made global footballing superstars who have often flopped (for example Andriy Shevchenko for £31 million or Luka Modric for £35 million) for massively inflated prices rather than create a solid base for the future by nurturing the club's youth academy and promoting younger players into the first team in order to maximise their full potential.
Whilst clearly this brings immediate success in terms of trophies, it financially destabilises a club in the long term and reduces their chances for success in the future.
Overall, this makes Jose Mourinho basically an overly expensive solution for merely short-term success: the Portuguese has never stayed at a club for longer than three years in his entire managerial career, and I would be willing to bet that nothing will change this time round.