He owned the best right-back crown for a considerable amount of time, but also impressed at left-back and on the right of a back three.
Dave, as he’s fondly called by Chelsea fans, was the player every team wanted: a defender who consistently delivered a solid 8/10 rating. With the former Marseille man setting himself such high standards, it was easier to spot when he was having a bad game.
A 6/10 performance from Azpilicueta was easy to spot. And such a drastic drop off would be a talking point among the Blues support. In many ways, the Spaniard had become a victim of his own success.
But his form across the past year has gone from being a concern to an issue. Last season, Sadio Mané ran rings around Azpilicueta at Anfield during the 2-0 defeat. That wasn’t the 30-year-old's first nightmare game of the campaign but it was perhaps the most memorable.
He’s started sluggishly this season, too, and was exposed in the recent 2-2 draw with Sheffield United. He let Enda Stevens easily dart past him to set up the first goal for the away side just after half-time.
Azpilicueta was also sloppy in possession throughout that half and often caught on his heels as Chris Wilder’s men ramped up the pressure. Christian Pulsic was pulled back to support the Blues right-back on countless occasions
Azpilicueta looks out of sorts in the youthful, energetic Chelsea side Frank Lampard has pieced together. Perhaps it’s the change in style which has exposed Azpilicueta’s weaknesses.
Chelsea are no longer defensively dominant and look play on the break. Instead, they’re a cavalier, high-pressing team which is reminiscent of the 2016/17 version of Liverpool.
Over the summer, the Blues moved on and their captain may have been left behind. Of course, he still has a part to play; his experience is invaluable to this young squad. But he should no longer be a guaranteed starter, and might not be when Reece James returns from injury.
The 19-year-old is yet to make his Premier League debut but was the star performer for Wigan Atheltic in the Championship last season. Signed as a right-back, it quickly became apparent he was too good to be limited to that side of the pitch and was used as a centre-back and in midfield. Tellingly, he didn’t look out of place in either position.
The step up to the top flight is a big one, yet James proved at Wigan he is worthy of an opportunity in the first XI at Stamford Bridge. And just as with Mason Mount, Tammy Abraham and Fikayo Tomori, Lampard has shown that a lack of experience at the top level isn't a hindrance in breaking into the Chelsea first-team.
James will make mistakes but it’s better for him to do and learn from them than have an ageing Azpilicueta continuously exposed.
The Chelsea youngster is, on paper at least, the perfect fit for what Lampard is trying to do at Stamford Bridge. He’s expressive on the ball, he’s used to a high-energy style and he’s diligent defensively.
James the real rival to Trent Alexander-Arnold as England’s future right-back. Aaron Wan-Bissaka is the flavour of the month but the way in which the Three Lions play means Gareth Southgate needs a right-back who is comfortable in possession.
They, at times, need to be something of a playmaker, too. Just as James was for Wigan and probably will be for Chelsea.
Azpilicueta can no doubt still do a job for the Blues but it might be painful viewing for fans. It’s through no fault of his own, either. He’s shown he can be adaptable in terms of position but the switch in style has exposed him. Some players thrive in defensive set-ups while others are better in attacking ones.
It just so happens Chelsea have adopted the latter while Dave is the former. He will be needed in certain situations but James has the ideal opportunity to claim the long-term right-back spot as soon as he’s back fit.