Gabriel Martinelli will miss more than a month of action after suffering a hamstring injury against Newcastle, according to a report.
Martinelli went down clutching his hamstring in the 37th minute at St James' Park.
Arsenal boss Mikel Arteta immediately signalled for teenager Ethan Nwaneri to come on following the blow.
Martinelli was seen limping off the field and the Brazilian is now set for a spell on the sidelines.
The loss of Martinelli will be another blow to Arteta amid a series of injuries in attacking positions.
Arsenal are already without Bukayo Saka and Gabriel Jesus, with the latter having been ruled out for the season with an ACL injury.