Eduardo da Silva, who this week made a two-goal return to Arsenal action after almost a year on the sidelines, will be out of action for another two weeks with a hamstring strain, the club said on Thursday.
The Croatia striker, who suffered a badly broken leg a year ago this weekend, helped Arsenal to a 4-0 victory over Cardiff City in the FA Cup on Monday but tweaked a hamstring shortly before being substituted after 67 minutes.
"Nobody knows how it happened but I knew straight away after the game it would be a two-week job," Arsene Wenger told Arsenal TV.
"It is nothing like he had before but I do know that little set-backs like this are part of being nine months out. But at the same time it is a blow because, of course, he can score goals."