Walcott has been out since mid-September after having minor surgery to repair a stomach muscle, leaving him unable to feature in England's recent World Cup qualifiers.
Wenger has admitted that Walcott's return to full training had to be scaled back after the winger complained of discomfort during sprints, meaning that his recovery will take at least two more weeks.
He told The Mirror: "He had a setback. He had to stop, to jog again, I don't think we will see him against Borussia Dortmund, nor Crystal Palace nor Chelsea. He is at least two weeks away now."