Havertz has been forced to withdraw from Germany's squad for their Nations League matches due to a knee strain.
There was hope the injury would only be minor, but football.london says Havertz could be missing for longer than initially expected.
When the season resumes this weekend, Arsenal will face Bournemouth, Shakhtar Donetsk and Liverpool over eight days.
And there's now a belief Havertz will struggle to make any of those three games as he continues his recovery.