Arsenal manager Arsene Wenger has confirmed that midfielder Aaron Ramsey will play no part in this Sunday's North London derby.
The Wales international was initially expected to return to action against Tottenham Hotspur after being on the sidelines with a thigh injury since December.
However, Wenger has revealed that Ramsey has suffered a slight setback in his recovery and will not be included in the matchday squad.
"We have had to defer his comeback to full training a little so he is not available," Wenger told the club's official website. "He is having difficulties in the final stages of his rehab. It looks to be short-term."
The Gunners will also be without midfielder Mesut Ozil, who picked up a hamstring injury during Arsenal's Champions League exit against Bayern Munich on Tuesday.