Reports have suggested that Southampton will rival West Ham for the winger's signature in January, in a bid to add some well-needed pace and experience to both respective rosters.
Alex Apati of Ladbrokes said: "Walcott has to leave Arsenal if he's to stand any chance of making England's World Cup squad next year, and a switch across London looks to be the most likely option right now".
Walcott has struggled to leave to his early potential with the north London side, and he now finds himself on the periphery of the first-team with Mesut Ozil, Alexis Sanchez, Alex Iwobi and at times Danny Welbeck preferred in a two-man attack behind the main marksman.
Arsenal manager Arsene Wenger (L) looks on as Theo Walcott takes a throw-in during the UEFA Europa League Group H football match against Red Star Belgrade. Walcott has been involved in more than one highly-publicized contract dispute since joining the Gunners, and it's now common knowledge that the English forward is earning in and around the region of £140,000 a week.
Academy product Jack Wilshere could also be on the move as he'll be a free agent in June and may seek regular game time in an effort to force his way into Gareth Southgate's World Cup plans.