"O'Driscoll has proved over and over again he can do that (raise his game)," O'Sullivan said.
"The huge element that underpins his captaincy is that all the guys know he has that capacity. He has developed as a player and a person.
"He's only 26 which is very young to be in this position. But behind that young age is a lot of experience.
"He has over 50 caps for Ireland and this will be his second Lions tour.
"He uses his experience very well and that will stand him in good stead."