The Gunners lost Cech during last month's defeat to West Brom and Koscielny was forced off during the draw with Manchester City two weeks later.
Both missed the victory over West Ham and subsequent defeat to Crystal Palace earlier this week, with Emiliano Martinez deputising in both fixtures following an injury to second-choice goalkeeper David Ospina.
Ospina remains sidelined, but both Cech and Koscileny are expected to return to the squad and will undergo tests ahead of Monday's trip to the Riverside Stadium.
The Frenchman said: “We have the chance to get Petr Cech back and Koscielny is joining in today. If the tests are positive they will be in the squad for Monday.
“Ospina and Lucas [Perez] are still out.”