The Reds finally lost Coutinho to the Catalan giants earlier this week, pocketing up to £142m with add-ons for their key playmaker.
Coutinho's departure opens a gap in midfield for Oxlade-Chamberlain to slot into, and the former Arsenal ace is prepared to make it his own after being eased into the role by Jurgen Klopp since arriving in the summer.
"Of course it's an opportunity for me, just as it is for all the rest of the boys who want to play there," he told Sky Sports News. "It is our job to keep the wheels moving and momentum going.
"I am the type of person who relishes the chance to stand up and perform under pressure, I have had to do that my whole career. I was at a big club previously and being at big one now, you know you are always going to have to perform under pressure.
"I haven't really even thought about Phil leaving. You realise it happens but you can't start thinking 'What are we going to do now that Phil is not here?' It can't be that at all. It's business as usual.
"When Phil wasn't in the team we still played great football and we have still amazing players who can score goals - the likes of Mohamed [Salah], Sadio [Mane], Roberto [Firmino]. The fact is he has gone now and we have to think 'What have we got that is going to get the job done?'.
"I have every faith in the boys that we just move on now. I don't think it should affect us at all. When a big player leaves, a big player leaves. You're at a big club like Liverpool, another big player will come in the future. I wish Phil all the very best but the only thing I'm concentrating on is Liverpool and winning as many games as we can - starting with Man City on Sunday."
Oxlade-Chamberlain has 19 Premier League outings under his belt since joining in a £35m deal, with 12 of those coming from the bench.