Trace the latest sequence of attacking full-backs under José Mourinho and you will find an unlikely member. In the Special One’s last three teams, a constant component has been a full-back pairing where one defends and one attacks. At Internazionale, Maicon hared forward while Cristian Chivu stayed at home. At Real Madrid, Marcelo bombed on and Álvaro Arbeloa held back. At Chelsea, César Azpilicueta defends, but here the wing-back is no rapid Brazilian. No, it’s 30-year-old former central defender Branislav Ivanović.

There is a conspicuous contradiction between Ivanović’s profile – tall, brave and strong, the typical central defender – and his adventurous positioning. The composition of Chelsea’s back four shuns what is ostensibly logical. Azpilicueta should play on the right, Filipe Luís should maraud down the left and Ivanović should dominate centrally. Instead Mourinho’s preference has triggered a reshuffle that appears unnatural.

Yet it is working. Besides fortifying the defence, Ivanović, who arrived from Lokomotiv Moscow in January 2008, has recorded 3 goals and 4 assists in the Premier League this season.

In the last five league games, the Serb has struck 1 goal and assisted 3. And let’s not forget the recent header against Liverpool that sent Chelsea to the League Cup final.

Brazilian beats

Ivanović's productivity is indeed impressive and would make more sense had it transpired solely from his aerial power at set-pieces. But it does not. More often, it is a consequence of advanced positioning that actually does resemble that of a full-blooded Brazilian wing-back.

Take some of his goals. Earlier this season at Goodison Park, Chelsea engineered a fine move that culminated in Ramires slipping a pass in behind the Everton defence.

Lurking inside the box was Ivanović, who finished low. Last Saturday at Villa Park, he ghosted into the area and produced a left-footed first-time drive into the top corner; a strike as sweetly struck as it appeared unlikely.

His ventures also underpin most of his assists. In Chelsea’s 2-0 win at home to Newcastle, Ivanović received a short corner and set up Oscar. It was a set-piece, yet it was taken so quickly after an attack that Newcastle failed to react, and Ivanović needed to be far upfield in the first place to take any part in it.

Later in the season, in the 5-0 drubbing of Swansea at the Liberty Stadium, Ivanović found Eden Hazard out wide and sprinted into the box. He got the ball back, touched it past a defender and set up André Schürrle with a low cross. It was textbook full-back play.

The curious thing about Mourinho’s arrangement is not that Ivanović plays at right-back – other Chelsea bosses have deployed him here too – but that the interpretation is so attacking. The extent of this can be appreciated by comparing the roles of Ivanović and Azpilicueta. One storms forward, the other stays vigilant.

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Short passes, direct runs

For all this, the technical limitations of Ivanović are apparent. And he will know it. His chief purpose is to stretch play and allow Chelsea’s attacking midfielders to drift inside between the lines.

When he does receive possession close to the byline, his choice is often a safe pass backwards or sideways.

His dribbling and pace are unremarkable, and he is more likely to bypass defenders by combining with team-mates rather than going solo. The stats reflect this. Despite frequently appearing in advanced positions, Ivanović has delivered an average of 0.3 crosses per match.

Even in games where Chelsea have enjoyed complete dominance, his decision-making has been conservative.

Instead he chooses a different route. Rather than trying to cross like Beckham and dribble like Messi, Ivanović prefers to foray into the box. His assists are delivered from close range, not far out wide.

Such runs also make direct goalscoring chances more likely to materialise, although his finishing can vary from the dazzling to the downright dreadful.

Serbian steel

Nonetheless, the solidity and stability Ivanović provides make technical shortcomings easier to forgive. At Chelsea, only John Terry matches his record of having played every minute of the league season so far.

Ivanović is rarely injured. In the League Cup semi-final second leg against Liverpool, he played on despite a cut in his foot that flooded his boot with blood.

That Ivanović can defend well and also contribute in the final third makes him a man for all occasions. Earlier this season, he created 6 chances in a routine 4-2 win at home to Swansea. In the next fixture, away to Manchester City, he transformed himself into a rearguard warrior tasked with shutting up shop.

An obvious bonus is his aerial ability. Crucial goals have been and will continue to be scored from set-pieces, while the prowess hands Chelsea an edge at goal-kicks as well.

No wonder Mourinho likes him. “I am very happy because he is a great guy,” the Portuguese said after the win at Villa. “What he is doing for us is unbelievable. The injury he had against Liverpool and played the rest of the game, played against Man City and played today – he’s a fantastic character.” It was also put to Mourinho whether Ivanović will be remembered as one of the club’s best signings. “I think so,” he replied.

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