O'Driscoll was taken off as a precaution in the 73rd minute

The Ireland captain was substituted seven minutes before the end of their historic Six Nations win over England but will be fit to face Scotland.

"Brian is fine," said O'Sullivan. "It's a fatigue issue, there's no issue with the injury.

"I was anxious to get him off because his hamstring tightened up again. For that reason I took him off."

O'Driscoll had missed the France match with a hamstring strain but returned to play an inspirational part in Ireland's 43-13 win over England.

SIX NATIONS BLOG In 45 years of watching international rugby, no game has matched the power, passion and emotion at Croke Park BBC blogger Jim Stokes More on our Six Nations blog

O'Sullivan explained that he had taken O'Driscoll off as a precautionary measure to preserve his fitness for the match against Scotland on 10 March.

"He could have finished the game but the danger is if he sees a gap, the crowd cheers and he takes it, he could end up damaging his hamstring," O'Sullivan said.

"He didn't want to leave because he was enjoying himself, but it was the right thing to do."

O'Driscoll's centre partner Gordon D'Arcy has also been given the green light for the Triple Crown game at Murrayfield despite tweaking his groin strain.

"Gordon D'Arcy's groin tightened up a bit but he was managing fine so we left him on," said O'Sullivan.

"We've been lucky with injuries so far in the Six Nations. There are two games left and we are in good health."

Meanwhile, O'Sullivan has added nine players to the squad for training this week.

They include Ulster quartet Tommy Bowe, Stephen Ferris, Bryan Young and Roger Wilson.