Arsenal boss Arsene Wenger has conceded he must do without Aaron Ramsey for another three weeks as the midfielder continues to struggle with a hamstring injury.
The Wales international picked up the problem on the opening day of the new Premier League season against Liverpool, although he was expected to return after the international break initially.
However, his comeback has slowly been delayed by the Gunners, and Wenger admitted on Friday that Ramsey is only likely to be available again after the next international break in October.
"Aaron Ramsey is still struggling with his hamstring," the Frenchman said at his pre-match press conference ahead of Saturday's derby clash with Chelsea.
"I don't think he will be available for our next game against Basel or at Burnley. So before the [next] break, he will not be available.
"He has a small Grade 1 hamstring [tear]. But he's not completely free in his mind yet to push completely. We stop him every time when he has a little pain. He's in the last, last days of his rehab. As long as he's not completely comfortable we don't push him."
Asked whether he was concerned about Ramsey's persistent hamstring woes, Wenger replied: "Not really because it's nothing major. But I'm a bit more cautious than I would be [if he had not had previous problems].
"If he was ready to play I would involve him in the squad of course, but he is not."