Arsene Wenger fears his Arsenal side could already be suffering from burnout, with less than a third of the Barclays Premier League season gone.
The Gunners slumped to a 2-1 defeat at Stoke on Saturday, with Rory Delap's devastating long throw teeing up goals for Ricardo Fuller and Seyi Olofinjana before Gael Clichy's deflected consolation.
"We tried hard to win but Stoke, at the moment, are very sharp physically," he said. "We looked a bit jaded because we have played a lot of games recently."
He added: "At the moment we are suffering. I don't believe it is confidence; we put a lot in on Wednesday night and we play again in midweek in Europe."
And injuries to Theo Walcott, Emmanuel Adebayor and Bacary Sagna at the Britannia Stadium, as well as a red card for Robin van Persie, are unlikely to ease Wenger's concerns.
He added: "We have very bad injuries. We have Adebayor, Walcott and Sagna as well as one or two others who have knocks, but that's the kind of game we played here.
"When you are not as sharp, you are less agile and you can't get as quickly out of tackles."
He added: "We had lots of possession against a team who defended very well and was very well organised, but we were not sharp enough to to create chances with the possession we had."
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