The Chelsea managers past and present are poles apart in personality, but only one thinks making enemies is part of the job

Nobody seems certain how soon the ­vendetta between José Mourinho and Carlo Ancelotti began after the arrival of the Portuguese coach in Milan in the ­summer of 2008. But the fires were ­certainly stoked when the Italian TV talkshow host Piero Chiambretti remarked that the difference between Internazionale’s new man and God was that God didn’t believe that he was José Mourinho.

It was Mourinho’s arch response – “Even Jesus isn’t loved by everybody” – that provoked Ancelotti to enter the debate last year. “If Mourinho is Jesus,” he observed, “then I am certainly not one of his apostles.”

No chance of that. When the two men were guiding the historic clubs who share occupancy of the Giuseppe Meazza stadium in the San Siro district of Milan, there was little doubt that they would soon be getting under each other’s skin. And the needling has been revived this week by the meeting of Mourinho’s Inter and Ancelotti’s Chelsea in tonight’s first leg of their Champions League last-16 tie, rendered all the spicier by Mourinho’s frequently expressed belief that the west London team remain very largely the fruit of his work at Stamford Bridge between 2004 and 2007.

In Ancelotti’s autobiography, published during his last year in Milan, Mourinho was lightly ridiculed as “the Great Commander, the King of the Media, the High Lord Specialness”. Mourinho responded by sneering at Italian head coaches who allow the owners of their clubs to pick their teams – an obvious jibe at the relationship between Ancelotti and Silvio Berlusconi, who certainly likes to make his opinions known.

Ancelotti weighed in with a pointed mention of Mourinho’s virtually nonexistent playing career. The Italian did not need to add emphasis by pointing to his own distinguished record with Parma, Roma and Milan, his honours including two league titles and two European Cup winners’ medals. Mourinho shot back by stating that no team of his had ever lost a big match after leading 3-0 at half-time, as Ancelotti’s Milan did in the Champions League final of 2005.

They are from the same generation – Ancelotti is 50, Mourinho 47 – and their clubs are sitting on top of their respective leagues, Chelsea with a four-point lead over Manchester United and Inter with a five-point cushion above Roma, but in almost every other respect they are as far apart as could be.

The phlegmatic Italian frames his thoughts deliberately, disguises his droll sense of humour behind a lugubrious facade and played down the animosity between the two at last night’s pre-match press conference. Nevertheless the Portuguese loves to wield a poison-tipped stiletto and at his own press conference he dealt with Ancelotti’s claim that the whole of Italy, Inter fans apart, will be supporting Chelsea by referring to his rival coach as “one of the clan”, with its mafia overtones.

In Italy, where they are not easily impressed by the handsome overcoats that seduced the English public, the media have less appetite for Mourinho’s ­effrontery and he is regarded – in the words of a correspondent of the Corriere della Sera – as “a stranger, practically an alien, who is finding it very difficult to adapt”. In his season and a half with Inter he has publicly fallen out with the presidents and coaches of several Serie A clubs, and last weekend the list of his enemies grew to include the president of the Italian football federation and the entire body of the country’s match officials.

After Mourinho responded to red cards for his central defenders Walter Samuel and Iván Córdoba in the first half of Sunday’s 0-0 draw with Sampdoria at San Siro by crossing his wrists as though manacled, he received a three-match touchline ban for the implicit suggestion that the officials had denied him and his players a fair chance to compete. Samuel and Córdoba each received a one-game suspension, half of that handed out to Sulley Muntari for aggressive dissent and to Esteban Cambiasso for trying to punch an opponent at half-time. Gabriele Oriali, a World Cup winner with Italy in 1982 and now an Inter director, was also banned for two games for persistently arguing with officials.

Although Massimo Moratti, Inter’s president, dutifully criticised the suspensions as unjustifiably harsh, he is known to harbour a distaste for the consequences of Mourinho’s inflammatory behaviour. But the coach was brought in to replace Roberto Mancini with the aim of capturing the European Cup, which Inter won during the presidency of Angelo Moratti, Massimo’s father, in 1965 and 1966, and success this year might persuade both parties to maintain a somewhat fractious relationship for another season.

Ancelotti has the same target, with an additional requirement to produce the sort of spectacular football with which Chelsea’s owner, Roman Abramovich, wants the club to be identified and which Mourinho, for all his five major trophies, was unable to provide. The Italian has done well in his seven months in charge at Stamford Bridge, despite, as Mourinho pointed out, losing four of his first 27 league matches.

In their winning percentages while in charge of Chelsea, the two managers are virtually neck and neck, with Mourinho at 67% over 185 matches and Ancelotti at 70% over 40 games. With the rival Milan clubs, too, their performance is remarkably similar: 56.7% for Ancelotti over seven seasons with the Rossoneri, 58% for Mourinho over a season and a half with the Nerazzurri. No current manager in top-flight football, of course, can match Mourinho’s ongoing personal record of 130 unbeaten home league matches in succession.

Apart from questions of character, the principal difference between the two may be the contrast between Mourinho’s faith in technical organisation, all ingrained systems and micro-management from the technical area, and Ancelotti’s more relaxed but still rigorous approach. For all the disparity of their methods, however, both command the enduring loyalty and respect of some of the game’s most famous players. But only one of them believes that making enemies is part of the job.

Champions LeagueJosé MourinhoCarlo AncelottiChelseaInternazionaleRichard Williamsguardian.co.uk