Jose Mourinho opted to bring Samuel Eto'o to Chelsea at the end of the summer transfer window, but instead should have signed the striker who revealed he "would have killed" while playing under the Portuguese coach at Inter Milan.
Zlatan Ibrahimovic's adulation for Mourinho is no secret. The controversial duo only worked together for one season at the San Siro - but rather than the fiery clash in personalities which everyone expected, it turned out to be a match made in football heaven.
As well as stating in one interview that he felt so motivated by Mourinho's words that he took to the pitch ready to kill, the Sweden international recently said in another interview that the Portuguese transformed him from a "cat into a lion".
Clearly, had the opportunity risen for Ibrahimovic to reunite with his former mentor he would have jumped at the chance. This is no one-club man we're talking about here; this is a player who rarely spends more than two years at a club and has played for seven different teams since 1999.
But we're also talking about one of Europe's most enigmatic and gifted strikers, capable of producing moments of sheer genius from nothing. A very different striker from Eto'o who, sadly for Chelsea supporters, looks to be someway past his best after losing a yard of the pace he has relied on throughout his career.
Rather than earning his cash in the Russian Premier League in recent seasons, like Chelsea's latest acquisition, Ibrahimovic has been earning his at Paris Saint-Germain, who have improved immeasurably since Zlatan's arrival.
The 31-year-old has never been the quickest of players, but could have played a similar role to the powerful Didier Drogba for a couple of seasons under Mourinho at Stamford Bridge.
Don't let the ponytail fool you: Ibrahimovic is one of the toughest footballers in European football. The 6ft 5in Taekwondo black belt was born and raised in one of Malmö's toughest neighbourhoods and can go toe-to-toe with any defender foolish enough to mess with him.
He would have had no problem adapting to the Premier League, while those who suggest he would have flopped at Chelsea because he "failed" at Barcelona should consider this: Ibrahimovic scored 16 goals in 29 matches at the Nou Camp, winning the La Liga title plus two Spanish Super Cups, one UEFA Super Cup and a FIFA Club World Cup title. Not bad for a so-called failure, eh?
The reason for Ibrahimovic's acrimonious departure from the Catalan giants was because of his relationship with Pep Guardiola, which rapidly deteriorated after a six-month honeymoon period. If anything, this must have enhanced his respect for Guardiola's nemesis, Mourinho.
PSG, of course, were desperate to keep Ibrahimovic. But after they forked out over £50m on Napoli striker Edinson Cavani, there must have been a realistic chance - however slim - that Chelsea could have tempted the Parisians to sell.
Instead, the Blues are left with Eto'o, who is unlikely to help Chelsea win any silverware this season - and won't be half as fun to watch, either.