The former England international, who played alongside the Arsenal manager during his stint at the club, has been training with his former team, following his exit from Besiktas.
Now, in a recent sit-down with Celtic TV, the club's new signing detailed the conversations he had with the former Rangers midfielder, who played in Glasgow from 2002 to 2004. "I spoke with him about it and he just explained how much of a perfect fit it would be," Oxlade-Chamberlain said.
"His words were that his time up here was some of the best of his career. He felt things that he didn't necessarily feel again, even at other big clubs that he played for. He talked highly of the rivalry, the passion, and what it means to everyone that's around here.
"He said it's a massive place, a massive club, and it will be an amazing fit. He spoke very highly of everything up here and how things go. That also helped to hear it from his side of things."
On his current fitness status, Oxlade-Chamberlain said, "I'm ready. I've been training for three months at Arsenal and running around there and keeping up with those boys. That has been really helpful for me to keep me in a rhythm and fit.
"The next step is playing games, and there is a different intensity to that. I'm ready to do that. It will take a little bit of time as it always does to get flying to your full match fitness, but in terms of being ready to go now, I'm good to go and excited."