It was clear during the match that many away supporters were sitting among Arsenal fans in the stadium, with some of them causing problems for stewards.
When you play at home, everyone expects you to win the games.
"The only thing I can tell is you need to see what happened before the tackle".
The Blues have recovered impressively with four straight wins after the opening-day home defeat by Burnley - but Stamford Bridge was seething with frustration at the final whistle here. "With a bit more freedom, I believe we would have won the game".
Arsene Wenger's side then went out and followed up their second PL victory with a comeback win over Cologne on Thursday in their Europa League opener courtesy of three second-half finishes.
Arsenal won the most recent meetings with Chelsea, claiming the FA Cup in May and the Community Shield, on penalties, in August.More news: Harry Dean Stanton of Alien and Twin Peaks Fame Dies
But the Italian stayed strong in his convictions and switched to a 3-4-3 formation which prompted a 13-game winning run in the Premier League title success.
Arsenal's display on Sunday, full of steel and discipline as well as attacking intent, gave the Frenchman's theory plenty of weight as they stood toe-to-toe with the champions and were the better side for spells. A unusual situation. I think it can happen, this type of period, if you are not so lucky.
"On Wednesday he'll have the possibility to start the game against Nottingham Forest and complete his recovery".More news: Iraq referendum : Parliament votes to reject poll on Kurdish independence
Aware that Liverpool exploited Arsenal's defensive flaws, Mertesacker says his side won't be so naive this time.
"We'll train hard these two days coming and we'll be ready for Sunday".More news: Twelve Nobel laureates pen letter urging United Nations to act on Rohingya crisis
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