Arsene Wenger has confirmed Aaron Ramsey will miss Arsenal's trip to Anfield to face Liverpool next Sunday.
The Wales international scored twice in midweek as Arsenal beat Galatasaray in the Champions League but was forced off with a hamstring injury that subsequently ruled him out of Saturday's win over Newcastle.
Ramsey is now set for a spell on the sidelines along with Laurent Koscielny with Wenger unable to say when the duo will be fit to return to action.
"Ramsey will be out for a few weeks and Koscielny as well," he told reporters. "They will not be back next week."
Arsenal's injury problems saw Mathieu Debuchy deployed as a centre-back in the 4-1 win over Newcastle, but Wenger says his side were much improved from Saturday's defeat to Stoke at the Britannia Stadium.
"I’m a bit scared to say that, but at Stoke we missed the start of the game and defensively," he added.
"You look at the chances we had at Stoke and we could have scored four or five there as well and we finished the game with 10 men. Defensively we were not at the races from the start and we paid the price for that.
"The fluency going forward was not disastrous, it was our defending that was not good."
The Gunners have now scored 10 goals in their last three outings but Wenger has denied his team are the most creative in the Premier League.
"We try. I don’t think we are the most," he explained. "It’s always the same in football - you try to attack to go forward and if you win everybody says well done, when you don’t win everybody says you’re not realistic enough.
"I think our target is to combine keeping our style and defending well as well - that’s what we did today."