On his first day at Chelsea nearly nine years ago, Jose Mourinho declared himself "a special one" and he will have to do something rather special on his return there to disprove the old adage that you should never go back.
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Time and again, managers who have returned for a second, or even in rare cases, a third or fourth spell at their old English clubs have failed to achieve what they did first time around.
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Mourinho has set his own bar very high at Stamford Bridge, becoming the most successful manager in the club's history during just over three years there by winning five major trophies between 2004 and 2007: the Premier League title in 2005 and 2006, the League Cup in 2005 and 2007 and the FA Cup in 2007.
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Chelsea never lost any of their 60 home league matches while Mourinho was manager, but the love affair came to an end in September 2007 when, after a series of fallings out with owner Roman Abramovich, he left "by mutual consent".
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He now returns after a difficult season at Real Madrid and will want to prove that unlike many other managers, the magic can work a second time.
I believe he would win the EPL next season with Chelsea. The team is just strong enough to do that.