Cesar Azpilicueta will treat David Luiz just like any other opponent when Chelsea face the Brazilian and Arsenal at the Emirates Stadium on Sunday afternoon.
Luiz was surprisingly sold to the Gunners by head coach Frank Lampard at the end of the summer transfer window and has struggled for form in north London.
Yet Azpilicueta, the Chelsea captain, is more interested on focusing his own team's erratic form having lost three of their past four home games despite impressing on the road.
"When I arrived he was here, then he went to PSG and came back," Azpilicueta said. "Now he's a player that was very important here, part of the squad that won the Champions League, two Europa Leagues and the Premier League with [Antonio] Conte.
"We know that football changes, players move here and move there. Now he's started a new chapter for him at Arsenal. On Sunday he will be a rival and we will fight for our teams."
Until recent years it was unusual for Chelsea and Arsenal to trade personnel so freely but after Petr Cech went from the Bridge to the Emirates, before returning in an off-field role this year, and Olivier Giroud went in the opposite direction it has become the norm.
Azpilicueta feels it is merely a symptom of modern football.
"Football in every country is very different. Sometimes the opportunity is to go there and there are clubs, players, agents, everyone involved and make decisions that they think is better for them."
Sunday will be Mikel Arteta's first home game in charge of Arsenal and Chelsea have also lost to Valencia and Everton sides buoyed by having a new face in the dugout this season.
"I never played with him," Azpilicueta said. "I know him because he is Spanish and played for Arsenal but I don't have any special relationship with him.
"He was in [Pep] Guardiola's staff [at Manchester City] and for them it's a new beginning and a new coach but for us it's a massive game.
"It's a derby and we need to bounce back after this disappointing afternoon [against Southampton]."
