Antonio Conte feels Cesar Azpilicueta is arguably one of the best players in the world in his current role and believes Chelsea's 3-5-2 formation fits the Spaniard perfectly.
Azpilicueta previously featured at either right- or left-back, but has impressed this term as the right-sided centre-back in a three-man defence.
The 27-year-old has played every minute of Premier League football this term - Thibaut Courtois is the only other Chelsea player not to miss a minute - and Conte has reiterated his integralness to the team.
"This system [3-5-2] was in my mind when we planned the season with the club," Conte said.
"We have two systems, 4-2-4 and 3-4-3. When I switched to this system, I felt it was a good fit for our players. We do not lose offensively but we are better defensively.
"We found players not to adapt, but to play in different roles compared to the past. Like Azpi, he is incredible in this new role. He is one of the best in the world in this role."
Victor Moses is another player who has flourished in a new position under Conte and the Italian was equally full of praise for the wing-back.
"Moses too," the Chelsea boss added. "To run for the whole game with this quality is fantastic."
Azpilicueta has one assist from his 26 appearances for the Blues in the league this season and is currently contracted to the club until 2020, having joined in August 2012.