Wenger had been hopeful last week that Ramsey could return from a long-term thigh problem to face Tottenham, but the Welshman has yet to recover fully from the injury.
The news is a blow for Wenger as he is already missing Jack Wilshere with a broken foot, while Mesut Ozil faces a spell on the sidelines after suffering a hamstring injury in the midweek Champions League defeat by Bayern Munich.
"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."
Wenger is still waiting to find out the full extent of Ozil's injury to determine how long he will be missing the German playmaker.
"He is out. I don't know for how long but it is a hamstring injury. There are scans going on," added Wenger.
However, Wenger is hopeful Kieran Gibbs and Nacho Monreal will be fit enough to return to the squad after being forced to play Thomas Vermaelen at left-back against Bayern Munich.
"Kieran Gibbs has a test tomorrow but I am hopeful that Nacho Monreal will be fit. They both have a good chance," noted Wenger.
January signing Kim Kallstrom could be included in the squad for the first time after recovering from a back injury and striker Yaya Sanogo is back in training after missing the Bayern defeat with a knock.
"Kallstrom joins the normal training group today and Sanogo too," continued Wenger.
"I will have to decide if Kallstrom is OK to be in the squad on Sunday. I will see how he looks, it is not impossible."
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