Welbeck is expected to be sidelined with a knee injury until the new year according to BBC.
“The injury to his cartilage did not respond as well as hoped and the decision was taken last week for him to undergo surgery,” said an Arsenal statement.
Özil is also currently out with a knee injury but the problem is not thought be serious.
The World Cup winner posted a picture of himself alongside Welbeck with the following statement, “Stay strong and get well soon, Danny! #Arsenal #AFC #Welbeck.”
Arsenal were the only club from the top five European leagues not to sign an outfield player during the summer transfer window.
Özil is expected to feature in Germany’s Euro 2016 qualification encounter with Poland this week despite suffering a knee injury which kept him out of Arsenal’s clash with newcastle.
The 26-year-old is also understood to be available for Germany’s clash with Scotland next week. Germany sit in second place in Group D with 13 points in six games.