The confirmed injury to Alexandre Lacazette could provide one of Arsenal's squad players the "opportunity" to stake a claim in the Gunners first-team, according to manager Arsène Wenger, but the French boss has admitted the news is a blow to his plans for the rest of the season.
Lacazette came on a second-half substitute in the recent north London derby, missing two golden chances to rescue a point for the Gunners in the latter stages of the match.
The former Lyon man was then forced to go under the knife on Tuesday to fix a swelling on his knee, something that could see the former Lyon striker sidelined for six weeks.
"It's a massive blow for us, but we have to find a solution and nobody could predict that," Wenger told beIN Sports. "But football is as well to [deal] with unpredicted things, and it's always a good opportunity to find somebody who steps in and does well."
The Arsenal manager will now be looking towards Danny Welbeck and Eddie Nketiah to step up in their Europa League campaign - which kicks off against Östersunds FK on Thursday.
Welbeck hasn't made a name for himself in north London for his goalscoring prowess, hitting the back of the net just 22 times in 92 appearances. However, the Champions League winner does offer the Gunners a devastating combination of pace and power.
In 18-year-old Nketiah, Arsenal have an academy star who - thanks to his brace against Norwich in the Carabao Cup - has already won over the red half of north London.