Arsene Wenger's side gave up their lead at the top in grim fashion as they conceded four times in the first 20 minutes on their way to a 5-1 defeat at Liverpool on Saturday.
Wenger was uncharacteristically harsh on his players - and himself - in the aftermath of the game, demanding a response against the champions on Wednesday night.
And the message has clearly got through to Oxlade-Chamberlain, who said: "We are very disappointed, especially with the first half. We know we are better than that so in that sense we are gutted.
"But these things happen in football and it is our responsibility to turn that around and we have great opportunity on Wednesday night.
"When the first goal goes in early you have to respond and see out the next 10 or 15 minutes. We failed to do that and, credit to Liverpool, I thought they were brilliant and we were not up to scratch.
"In the second half we knew we had to improve and I believe that we did that. So there are some mental positives but we have to put it right on Wednesday."
Wenger said on Saturday: "I just think the whole team have failed to turn up with the right performance. We know that you need to be better focused at this kind of level.
"Overall our performance was just not good enough, and I include myself in that performance."