Arsene Wenger said he had cause for concern after Arsenal were beaten 1-0 at home to Newcastle.
Andy Carroll’s header on the stroke of half-time meant the Gunners suffered their second defeat in front of their home fans this season, which also brought an end to a three-match winning run in the Premier League.
“Our home form is a concern, because even against Birmingham and West Ham, they were struggling wins,” Wenger said. “When we score the first goal we play all right, but when we concede it’s difficult.
“It’s a big disappointment for us today. We did not look sharp from the start, and we never found the sharpness we wanted. We couldn’t find our second gear.”
Wenger defended the performance of goalkeeper Lukasz Fabianski, who was left stranded when he came out to claim Joey Barton’s free-kick for the goal.
“It was not a technical mistake – it was a problem of timing. That’s the impression I had from the outside,” he said.
“I believe our two centre-backs handled their strikers very well. They both had very good games, and I thought they were our best players today. Carroll is a handful, though.”
Newcastle boss Chris Hughton was delighted with Carroll’s performance.
“Of course what he does have is the prowess in the air but he showed also the running ability he’s got,” he said.
“He’s still learning the game, he’s getting better. He’s had his ups and downs and he gets bullied at times, all of these things, but he’s certainly going in the right direction.”
He added: “I think he was delighted with the quality of the goal.
“These are big weeks for us and they’re big games. We have a group of players who are in this together.”
Midfielder Joey Barton added “We’ve had our knockers and we’ll continue to get them but it just makes the group stronger and everyone’s 110% behind every other player, and it’s fantastic to play in.”