It’s funny how football can work out. Back in 2010, a 21-year-old Cesar Azpilicueta suffered a career low. Or so he thought. A few minutes after kick-off in Marseille’s 4-0 home League win over Montpellier, the full-back felt his left knee go. It was a rupture to his anterior cruciate ligament, the kind of injury that, at such a young age, can completely change a player’s future. It certainly did that – but not how Azpilicueta expected.

Despite the obvious “pain” and “sacrifice” the Spaniard says was involved, he credits the repercussions of his injury and the subsequent six-month lay-off with changing him into a completely different type of defender. It just so happens to be a type Mourinho greatly appreciates.

“Before, when I was playing in Osasuna, my body was different,” he explains. “After the injury, I think my physique got another dimension and I became stronger. I worked. You need to be strong here.”

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Azpilicueta has certainly illustrated that at Chelsea where he has surprisingly become the sturdy foundation on which Mourinho’s new defence is built – and begun to harden. The full-back has started 14 of Chelsea’s last 16 games in all competitions and developed into one of the most used but understated members of the squad.

Despite Mourinho’s preference for a team filled with premium stars, he has always specifically relied on a core of resilient but relatively unfashionable lieutenants. And Azpilicueta is a prime example. In October, ahead of Chelsea’s home win over Manchester City, Mourinho praised the 24-year-old as a player who puts the “team first, the team second and the team third... pushing others in the same direction”.

Unlike the other top-four teams, Chelsea have not suffered a defeat against their direct opponents. They retain an inherent durability. And Azpilicueta relishes the conservative side of the game. “I enjoy when I defend well and the team keeps a clean sheet. It makes you feel strong.”

At first, Mourinho didn’t seem to really like Azpilicueta, possibly viewing him as a Rafa Benitez player, and by early November he had still to start a League game.

Azpilicueta admits now that being away with Spain for the Confederations Cup just when Mourinho was looking to first figure out his new team had not helped. “I came three weeks later so missed the team’s early preparations. I kept working since that day and knew that if I had the chance to show the manager if he needs me, I will be there. I knew I could be better and try to give everything.

“He did say to me he had confidence in me and that I would have time to play – but I earn it on the pitch. That’s the most important thing.”

Mourinho clearly respected his attitude and soon began talking enthusiastically about the defender, in private and public. The feeling is more than mutual. “It’s exciting to work with him,” Azpilicueta gushes. So, what is it exactly about Mourinho that ensures the majority of players so buy into his methods?

“I think it’s the way he is, the feeling,” the Spaniard explains. “He has everything [as a manager]. He’s complete. Every game we play, we know the opponent so well and how to play. I learn a lot.’’

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Today against the struggling champions Manchester United, Azpilicueta will likely be in the line of fire, charged with either keeping down the electric Adnan Januzaj or preventing David Moyes’ more prosaic tactic of trying work most attacks down the wing.

It remains to be seen whether Azpilicueta will be paired with Ashley Cole, but that is the other aspect about the Spainard’s conversion: he has often kept out one of Mourinho’s favourite players and England’s premium left-back.

“I know he’s been playing there for a long time,” Azpilicueta says matter-of-factly. “I try to play, he tries to play, and do our best after the manager makes a decision.”

Chelsea’s defence is starting to resemble the niggardly unit of old, conceding just once in the last six games. Mourinho puts it down to a period before Christmas when they finally had time to step back and assess. “We had a big improvement in one week where there was no match, and we dedicated that week to certain aspects of our defensive game. It was just about the visual feedback, with images and computer work, not on the pitch. It was like a turning point. I think the team became much more solid.”

Azpilicueta concurs: “We have more stability, we have more time to prepare and the team, same as me, are settling really well. To be a big team, you need to play with the same players, the same manager. We are in a high level, so I think now we are starting to get that, and I think everyone is feeling on the pitch that we are starting to be a better team.

“Now hopefully, we will have a period of stability, with good results and everybody happy - and trophies.”

Cesar Azpilicueta is supporting Right To Play’s 5k run in Battersea Park on Friday 16 May. Right To Play is Chelsea FC’s global charity partner and uses sport and play to educate and empower over 1 million children every week in disadvantaged communities around the world. Sign up to the run at www.righttoplay.com/kickoff5k

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