Arsenal manager Arsene Wenger has confirmed that midfielder Aaron Ramsey will be on the treatment table for three weeks with a calf injury.
The Wales international suffered the blow during the Gunners' 2-1 defeat to Watford on Tuesday night.
The problem depletes Arsenal's midfield, with Santi Cazorla still injured, while Granit Xhaka is suspended for Saturday's clash against Chelsea at Stamford Bridge.
Despite the problems in the middle of the park, Wenger has insisted that he will not recall Jack Wilshere from his season-long loan at Bournemouth.
"I would say 21 days [on Ramsey]. Yes, we are a bit short at the moment but I think we have young players who can do well in there," The Mirror quotes Wenger as saying.
"We have Adelaide, we have of course [Ainsley] Maitland-Niles, we have Chamberlain. Iwobi can play in there. Elneny will come back after Sunday, so I still have some strengths.
"I think we have agreed for [Wilshere] to go for one year on loan and we will accept that. I would like to reiterate that we didn't push him out. He wanted to go somewhere and play and I agreed with that."
Arsenal head into tomorrow's game nine points adrift of Premier League leaders Chelsea.