The England international ruptured the anterior cruciate ligament in his left knee during Arsenal's FA Cup third round win over rivals Tottenham and subsequently missed the remainder of campaign.
Walcott's injury also kept him out of the World Cup in Brazil and the 25-year-old has yet to feature for Arsenal this term.
However, the former Southampton man was back in action at the club's London Colney training ground, along with Serge Gnabry, on Monday and could hand Arsene Wenger a timely boost in the coming weeks.
The Frenchman is currently without striker Olivier Giroud due to a fractured tibia but Walcott's likely imminent return will further strengthen a forward line that includes the likes of Danny Welbeck and Alexis Sanchez.
Walcott had been in strong form prior to his injury, scoring six goals in 18 appearances for Arsenal across three competitions last season.
Gnabry could also bolster Wenger's options - with the 19-year-old forward having been out of action since April due to a knee injury - and may help fill the void left by Mesut Ozil's absence.
The club's record signing is set for a three-month lay-off due to a knee problem.
