Earlier on Saturday the BBC said the 31-year-old Sweden midfielder faced a lengthy spell on the sidelines after picking up the injury the day after completing a loan move from Spartak Moscow.
Communications director Mark Gonnella told Reuters the injury was not sustained in training and that the London club were "aware he had a problem through medical checks".
Arsenal, second in the Premier League, host Crystal Palace on Sunday.
(Reporting by Sam Holden; editing by Pritha Sarkar)
