O'Driscoll, who at 35 is in his final season in professional rugby, has made three appearances so far this RaboDirect PRO12 campaign but is expected to start for Ireland this weekend.
And after filling O'Driscoll's boots for much of this season with Leinster, Fitzgerald, 26, is certain he can make the shirt his own.
"I'd say a big part of it is getting some time at 13 and making decisions under pressure. That's a strength of my game," Fitzgerald told the Irish Independent.
"In attack what I have learnt in the last month or two or three is you've got to trust the things I am good at and maybe I was focusing on trying to be a bit too much like what Brian does really well. We're very different players.
"You can't be what you are not. You've got to be good at what you are good at; that's not to say you can't improve different aspects, but I would say time in there is key.
"What I would really like to do if I got some games would be to show him the games and say, 'What do you think, what small things would you try and improve or change here'.
"You can add small bits but you can't change who you are really. You've got to a certain position and it is trust in yourself that got you there."
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