The players will train at Stade Bordelais tomorrow morning before the team announcement is made for the Namibia game and the vibes from O'Sullivan would suggest that O'Driscoll, who has made a quicker than expected recovery from a fractured sinus, will line out against the Africans.
"Brian and Shane (Horgan) are in great form. Brian took a full part in training yesterday and I think the medics are happy to clear him for this weekend's game. That's a great boost for everybody," the Irish coach told RTE Radio 1.
"I'm happy with Shane and the progress with his knee. He's a little bit behind Brian but he's still ahead of schedule. I don't think Shane will be ready this weekend but certainly he looks good for the week after against Georgia."
Flanker David Wallace seems primed to play on Sunday after seeing off an ankle problem, with O'Sullivan adding: "David has taken a full part in training for the last few days and he's had no reaction so it's all good."
O'Sullivan admitted Ireland "are where we need to be" in terms of training and match preparation, and said there is a lot of positivity in the camp despite the side's failure to hit top form in the recent warm-up matches.
"Probably the disappointing aspect of our preparation has been the performance against Italy. I was disappointed with that and I said so after. We didn't get into the game very well, we know what went wrong there and we'll just get on and fix it.
"Fellas have trained very well this week. We've the game coming up on Sunday and it should go well for us if we do the right things. It's all positive at the moment. We've got to keep in mind that these warm-up games are just warm-up games and there's no point peaking for those and not performing in the real thing."