The signing sparked an ecstatic reaction from the club's supporters, and Gazidis was delighted to secure such an exciting player.
"It is fantastic, that's what this is all about - making sure the club progresses and that we make our fans happy and proud," the chief executive told Arsenal Player.
"It is a brilliant feeling when we are bringing players in and winning trophies.
"We have been really clear, we will only bring in players who can really add to the squad and we do think he is world class. He is a great signing for us.
"It is a great step, and takes us one step closer to where we want to be."
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