Chelsea are at a different stage of their development to Arsenal, claimed Graham Potter after the Blues' defeat to the Gunners at Stamford Bridge.
Gabriel Magalhaes bundled home for Arsenal shortly after the hour on Sunday to seal a 1-0 win that sent Mikel Arteta's side back to the top of the Premier League.
It means Chelsea are now without a win in four league matches, while they have lost back-to-back top-flight games for the first time since December 2020.
Chelsea sit seventh, 13 points behind Arsenal, with just one league game remaining prior to the World Cup.
For Potter, who took over from Thomas Tuchel in September, Sunday's result was merely evidence of the work Chelsea have ahead of them.
He told BT Sport: "We're playing against a team in a really good moment, a confident team, but the boys gave everything.
"It was a huffing and puffing performance from us without the quality we really need, over the course of the game not too many complaints with the result.
"Don't think it was a lack of urgency, have to look at where the two teams were at. Arsenal have good confidence, they've been working together for a long time, a good understanding of what they're trying to do.
"We're probably at a different phase. We probably tried to make the game a bit more of a London derby, and maybe that's why we lacked a bit of quality. The effort was there, we were beaten by the better team.
"It's an indication of where we have to work, where the process is and where we have to do better, that's where we're at."
It was a particularly frustrating day for Pierre-Emerick Aubameyang, who endured a miserable reunion with his old side.
Aubameyang had just eight touches in his 64 minutes on the pitch, managing only one shot, which was blocked.
Potter, however, refused to pin the blame on any individual, saying: "I think it's part of the team, we didn't function as fluently as we would like.
"There's always two teams on the pitch, you have to understand where they're at, they come with good players and a good structure, Mikel's done a good job there, so you can see the points they have, they're in a good place and we're slightly different.
"You can have those moments in a season, what's important is we understand where we're at, what we have to do better and then execute it."