The competition for places in the centres for the men in green has become somewhat easier following the retirement of Ireland's record cap holder O'Driscoll - who starred in the Lions' successful tour to Australia in 2013.
And Fitzgerald admits O'Driscoll's influence lives on as the 27-year-old bids to follow in his hero's footsteps.
"I just watched Brian for a long period and we were pretty close. I was defending outside Drico for a long time," Fitzgerald said.
"You pick lots of different things from different guys. For me, always D'Arcy was the best to watch, because of his footwork and the stuff he could do. He's a dream to defend outside. He makes really good reads.
"When he's in the mood, there's no better player to defend with. His lateral movement is just huge.
"And obviously you learn a lot off Drico. When things got tight, his top ten per cent, his head: that was the stuff you learned from Drico.
"He was just a hard, hard man, and that was the stuff I loved about playing with Drico.
"All the fancy stuff, you can take all that; he's the guy you want to go to war with.
"So that's what you learn off those two guys - great players."