The experienced German has made over 200 appearances for Arsenal since arriving from Werder Bremen in 2011, but has not yet featured for the Gunners this season.
As it stands, Shkodran Mustafi and Laurent Koscielny are both ahead of Mertesacker in the pecking order at the Emirates, but the 32-year-old is confident that his career with the London club is not finished.
"I believe that I can reach a level again on which I am important for the team. I have the feeling that this is not the end," Mertesacker told Kicker.
"I look at the perspectives for me and my family, and I think that I'll intensify those thoughts from January on. That's also the time when you can listen to other things (offers) when your contract is expiring."
Mertesacker's current contract at Arsenal will expire at the end of the season.