Alexandre Lacazette injured his groin during Arsenal's 5-0 victory over Huddersfield Town on Wednesday and "might be out for a while", according to manager Arsene Wenger.
Former Lyon striker Lacazette opened the scoring at the Emirates inside three minutes but was replaced by Olivier Giroud at half-time.
Wenger revealed after the match the 26-year-old sustained an injury that will rule him out of Saturday's highly anticipated clash with second-placed Manchester United and potentially longer.
"It is an injury. It looked like a groin injury and he is definitely out of the weekend. He might be out for a while," said the Arsenal boss.
The loss of Lacazette will be a blow for the Gunners, but Giroud will be hoping his two-goal display against Huddersfield will be enough to convince Wenger to hand him a first Premier League start of the season against United.
Danny Welbeck could also be deployed against his former club, while Alexis Sanchez could move into a central role should the manager bring Alex Iwobi back into the starting XI.
-- Arsenal FC (@Arsenal) November 29, 2017