The 23-year-old has scored three in his last four games for the club, most recently in the 3-0 win over Wolves on Wednesday.
That goal takes him to 11 for the season and he has admitted that he is full of confidence and is enjoying his football after initially being held back by injuries earlier in his Arsenal career.
He told the club's offical website: "I'm 23 now and I am still growing. I am not afraid of getting hurt.
"A few years ago I had shoulder injuries, ankle problems and back problems and that was just me learning the other side of the game.
"Now I am just going into games and enjoying myself, not being scared of anything. The manager always tells me not to be afraid going into tackles. I am a totally different Theo Walcott now.
"We are playing great football and it's nice to be part of that and not on the treatment table."