The England international was handed a start at St James’ Park and confessed he felt slightly off the pace.
The Gunners were in need of a good result at St James’ Park after an underwhelming start to the campaign, and were handed all three points when Fabricio Coloccini put the ball through his own goal early in the second half.
Oxlade-Chamberlain was handed a rare start for the Gunners to add dynamism and intent in the final third.
The England international admitted that he was slightly off the pace given that he has had to sit and watch on from the bench in recent games.
“I felt a little bit off the pace,” he told the Arsenal official website.
“The last time I started a match was three weeks ago and you can lose a bit of match fitness in that time.
“That’s what I felt like today. In spells I showed what I can do but overall I think I was a little bit off the pace.
“But that comes with a run in the team and playing more matches so I’m sure I’ll be able to get back to my full match fitness in no time at all.”
Arsenal have an embarrassment of riches in attacking midfield, with Oxlade-Chamberlain battling against the likes of Aaron Ramsey, Mesut Ozil, Alexis Sanchez and others for a place in the starting XI.
The Gunners have now picked up seven points from a possible 12 heading into the international break and will look to build a bit of momentum to put forward a consistent title challenge this season under Arsene Wenger.