The opposing skippers will wear the number 13 jerseys in the one-off Test on Saturday in what will be a pivotal midfield match-up.
And although O'Driscoll admitted Mortlock was one of the best players in the world, the 29-year-old said he will be trying his best to find a weakness he can exploit.
"You always look forward to pitting yourself against the best centres in the world and he (Mortlock) has been the best centre in the world for many years," said O'Driscoll.
"I haven't seen a huge amount of the Brumbies this year and seen what form he is in, but when I look at some of the video footage it definitely refreshes my memory as to what he is good at and if there is anything I can try and exploit.
"But the guy has so much Test experience and is so comfortable in that arena that it often takes something big to try to overcome, and I will do my level best to try to do something."
Mortlock was just as complimentary of O'Driscoll when asked about how he will approach the duel.
"He (O'Driscoll) is a great player and I will certainly have to be on my game defensively," said Mortlock.
"He is a very enterprising and attacking player.
"He is a great defender, he rips into the breakdown, particularly out wide so I always look forward to marking Brian."
While many eyes will be on the battle between O'Driscoll and Mortlock, Wallabies debutant Luke Burgess will be matched up against experienced Irish scrum-half Peter Stringer.
O'Driscoll claimed Stringer thoroughly deserved his place in the starting XV and is confident he will be able to match it with the rookie Australian number nine.
"What Stringer has is an abundance of experience and confidence," added O'Driscoll.
"He is probably one of the best passing scrum-halves in the world, if not the best. That extra second from a back man point of view can be invaluable and hopefully it will be."
Burgess was one of four debutants that coach Robbie Deans named in Australia's 22-man squad today, with Peter Hynes named on the wing and Dean Mumm and Ryan Cross selected on the bench.
With so many new faces in the Australian team, O'Driscoll said he expects the hosts to take some time to settle early in the opening half.
"They will be trying to play their way into it and not pull out any miracle plays early on," he added.
"They just want to grow in to playing Test matches again - it is their first Test match of this season and the build up to the Tri-Nations and I think they will just try to get comfortable with one another and forge those partnerships."