Speaking after the game, Leinster coach Michael Cheika said: "The injury doesn't look too serious. Brian has taken a knock on his knee, and we made the decision to take him off at half-time."
O'Driscoll's successor as Leinster captain, Leo Cullen, also had his evening cut short. The second row unfortunately fractured his collarbone and any hopes of him featuring in the Ireland squad for the upcoming autumn internationals are gone.
O'Driscoll has had a timely return to form with Ireland's opening match of the season against Canada coming up on November 8.
The Croke Park clashes with New Zealand and Argentina follow after that, and speaking last week, Ireland's long-time captain said he was determined to fight for his place in new coach Declan Kidney's team.
"With a new coach, there's a great opportunity for everyone - everyone's on a level playing field and reputations don't really count for a huge amount," he said.
"With Declan, one thing about him that the lads will enjoy is that he is very much a guy that picks on form. No one will be guaranteed a place.
"A seasoned international is probably entitled to have one bad game but probably not two.
"So you know when you pull on a green jersey, you have to play well or someone will replace you."