Walcott suffered the cruciate knee injury against Tottenham in a 2-0 FA Cup win in January and subsequently missed the remainder of the Premier League season, as well as the World Cup.
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Although the 25-year-old is happy with the recovery process, he chose not to put a time frame on when he will back in action.
"The knee is going really well, I am doing some good stuff with the physios and fitness coaches and we have worked really hard throughout the summer," he told the club's official website. "Things are looking really good and I have worked very hard for the last five months now. Things will be fine.
"The most important thing is getting the strength back and it has pretty much nearly healed - it is just about building up that stability and strength again.
"Hopefully I'll be back out on those pitches soon. It is coming along nicely and I am really pleased."