Keen to avoid another damaging dismissal at Stamford Bridge this weekend, the Chelsea boss told his players to focus on keeping their emotions in check, while also placing the spotlight on referee Michael Oliver.
Arsenal have launched a full review into the circumstances surrounding the game. If you remember the first goal was very odd, I am sure that this goal [should have been] disallowed instead. Bellerin is aware of Arsenal's poor record at Chelsea's home and has warned his teammates it would not be an easy task to walk away from west London with three points.
Arsenal return to Premier League duties on Sunday, travelling to Stamford Bridge to face a deceptively improving Chelsea side who have somewhat slipped under the radar thanks to an underwhelming transfer window and opening day loss to Burnley.
The Italian also doesn't feel Chelsea have any advantage over Arsenal despite getting extra days to prepare this week as Wenger rested a number of players against 1.FC Koln in the Europa League on Thursday night. "They won the league previous year so we obviously know they are a very strong team", he said.
He added: "I think Arsenal is one of the six top teams in England they will they have a really good squad to fight for something important, the title for sure". Then we changed our system because after that game I understood very well our team.
"We have to draw a line under what happened and move forward".
'They were always special games for me because Arsenal are a good club to be playing against but I always felt at that time we were mentally stronger and we were the better team, ' he said.
"When you lose there is always disappointment, but I think last season was a great season for us, a big achievement". "We are working a lot on this aspect with him". "I don't know but they did it very well".
Like Costa, England midfielder Danny Drinkwater will not be involved against Arsenal, with his debut delayed until October by a calf injury.
"It is very hard to see him (returning) before the worldwide break". He needs time to recover.