In order to sweeten the deal, Arsene Wenger begrudgingly allowed him to lead the line through December and was rewarded with four goals. Has the decision backfired on the Frenchman?
It's pretty obvious what Walcott's strength is—blistering pace. He loves to run off the shoulder of the defender and latch onto a through-ball, and that's exactly what he did for Arsenal's first goal.
It was Thierry Henry-esque the way he cut in from the left after breaking the offside trap, and his finish was of the highest quality.
His second—given time and space to spin and pick his spot from 12 yards—was a finish most would expect him to bag, while the third was a sublime chip after an admirable endeavour.
But despite his obvious brilliance at the Emirates Stadium, is Walcott the man to take Arsenal forward, and could he feasibly play striker at any club?
The concern revolves around his one-dimensional nature—that being the limited nature of his strengths. Can a top side in 2013 get away with playing him as a pure poacher?
Take the Darren Bent situation at Aston Villa as an example. He doesn't get into the side due to his limited skill set in every aspect of the game other than inside the 18-yard box. He struggles to pass, can't join in with the buildup play and rarely touches the ball in any other parts of the pitch.
Walcott, it has to be said, is a similar animal. He's shown time and time again he can't really pass that well despite being ingrained into an Arsenal system that has done nothing else for years now.
Wenger's saving grace in this respect is that he has a crop of players able to drag themselves up the pitch and into attacking positions without the help of a forward.
Mikel Arteta, Jack Wilshere and Lukas Podolski are all talented enough and good enough on the ball to stream forward without hefting a 25-yard pass to a target man. Walcott's ability in this area isn't strictly relevant, but do we have any evidence of Walcott as a striker against a top team?
Newcastle were a weakened side. James Perch was an emergency fill-in at centre-back, while 19-year-old Gael Bigirimana was a forced option at central midfield. Wilshere and Co. had no problem bossing the midfield in this game, and Walcott wasn't required to help.
What happens when Arsenal face Manchester City and need a striker to help them out in the battle for possession? Can Walcott be relied upon to do that, or will he be eaten alive by Vincent Kompany?
While it's wrong to completely dismiss the suggestion Walcott cannot play as a modern centre-forward and label him "just another fox in the box" like Michael Owen was, it's also silly to get carried away.
Walcott has scored two hat-tricks, but they've been against poor teams in Newcastle and Reading, and he also drew a blank accompanied by a poor performance against a well-drilled, possession-hungry Wigan side.
We'll have to wait and see how he fares, but so far Walcott has genuinely shown us nothing other than what we already knew—he's lethal running on the last man's shoulder.