Adaptable Azpilicueta a central figure in Chelsea's impressive new formation
Middlesbrough v Chelsea, Sky Sports 1, 4.0
Jamie Vardy may have been given the man-of-the-match award for his performance for England against Spain on Tuesday, but to many Chelsea fans he was a damnable villain.
That's because a wretched tackle in the opening minutes by the Leicester striker - too keen to impress would be the generous interpretation - risked inflicting serious damage on a player who has become quietly vital to the London club.
As Vardy hurled himself studs-first into a challenge in the fifth minute and connected first with the ball but then with the left shin and right ankle of Cesar Azpilicueta, the Spaniard screamed with pain and Chelsea fans watched with dismay.
Vardy was lucky not to be booked; Azpilicueta was fortunate not be injured. Everyone at Chelsea was just grateful that Azpilicueta was able to finish the match and return to Stamford Bridge fit and ready to continue playing a key role in the transformation of Antonio Conte's team, who go to Middlesbrough today in search of a sixth Premier League win in a row.
In the past five league matches Azpilicueta has excelled in a new role for Chelsea.
He spent most of the last two seasons as a left-back, performing with real élan there without quite reaching the heights of peak Ashley Cole.
The signing of Marcos Alonso for £23m in the summer was intended to provide a longer-term solution on that flank and allow Azpilicueta to resume playing as a right-back, which was the role Chelsea envisaged for him when signing him from Marseille in 2012 for £6.5m, a fee that has since proved to be a bargain.
Azpilicueta did fine at right-back in the early matches of this season but Chelsea, as a whole, were defective. The manager recognised the need to change the team's set-up, and one of the alterations involved assigning a new role to Azpilicueta.
Since the game against Hull on October 1 he has been playing on the right-hand side of a three-man central defence. Chelsea's record since then reads: played five, won five, scored 16, conceded zero.
Conte believes he has found Azpilicueta's best position.
"'Azpi' is a fantastic player because he can play different roles but I think the role that he's playing now is perfect for him," says the manager.
"He's playing very well because he's fast, has good technique and he's a clever player. He can play in different roles but this role, I think, is perfect for him."
Azpilicueta is quicker than the other two centre-backs, Gary Cahill and David Luiz, and has a defensive instinct that can only have been enhanced by having played all across the backline. And despite a mostly mellow demeanour he plays with an iron will.
Azpiliceuta's excellence has been one of the reasons why Conte has not felt the need to try to wring more service out of John Terry in recent weeks, nor rush Kurt Zouma back.
Instead the 22-year-old Frenchman will continue his comeback from knee ligament damage by playing for Chelsea's Under-23s tomorrow.
No wonder Conte sees no reason to test Azpilicueta's versatility anew, especially with Victor Moses thriving at right wing-back.
Conte admits he has been pleasantly surprised by how quickly his players have adapted to the new system, which he felt compelled to introduce after the 3-0 drubbing at Arsenal at the end of September.
"It's not the same to play with four defenders and to play with three defenders," said the Italian.
"But the first two weeks we worked a lot - above all the first week - because we changed it after Arsenal, before Hull City. Then there was the international break. Then we started to work very hard to find the right line of passes with the ball and to find the right situation defensively. But yes, I'm surprised at the speed to understand this new change."
If Azpilicueta's role in Chelsea's improvement has been relatively unheralded outside Stamford Bridge, there has been no overlooking the thrilling performances of several players farther forward, such as Diego Costa, Pedro and, in particular, Eden Hazard.
The system change seems to have unlocked something within the Belgian, who in recent weeks has regained the form that made him the Premier League Player of the Year in 2015.
"I like to see my players always involved in the project, in the idea of football, when we are playing," says Conte.
"You can see Eden is always involved in the game, not calm and off during the game. No, he always stays in the game and he's always a point of reference for his team-mates.
"We have many players that can be decisive. It's important to put these players in the best condition for their talent and for me it's important to see that they put themselves, their talent, into the team."
Sunday Indo Sport