Even though coach Matt Williams has a wealth of inside knowledge about the Irish side after his time at Leinster, it is difficult to see any way the hosts can be prevented from lifting their first Triple Crown since 1985.

O’Sullivan admitted his side will emerge victorious if they play to their true potential but despite Scotland’s miserable form, he has seen enough to know they could turn out to be dangerous opponents.

“No-one would deny Scotland have had a difficult season but they are notorious party-poopers and know if they could beat us on Saturday, it would turn their whole campaign around,” claimed O’Sullivan.

“They are due a big performance and they tend to deliver them after they have been completely written off.

“Overall they have quite a good record against us so they will have no fears about coming to Dublin.

“I am sure they will have packed the kitchen sink before they leave Edinburgh and we are expecting a full frontal assault.”

In the aftermath of Sunday’s Murrayfield debacle, Williams was left scratching around looking for reasons to be cheerful amid another depressing defeat. From a cursory glance at the video, O’Sullivan claims to have found some.

“When they played a direct game, ran hard lines and recycled quick ruck ball they looked quite dangerous,” he said.

“They had France in trouble a few times but either threw a pass to ground or knocked-on. If they hadn’t made those mistakes, the scoreline could have looked a bit different.

“On form, I know we are the favourites and we are clear in the thought that if we perform to our ability we will win the game. But there is always the fear things might go wrong, sport can be like that and depending on how Scotland play they could be a real handful.”

O’Sullivan has made two changes to his starting line-up, recalling fit-again Paul O’Connell to the second row and drafting flanker David Wallace in for broken arm victim Keith Gleeson.

While O’Connell’s return was automatic once his fitness was confirmed after he missed Saturday’s win over Italy with rib damage, Wallace is back from the wilderness.

The Munster back row has not started for his country since the World Cup warm-up win over Scotland last September.

He failed to make O’Sullivan’s squad for the trip to Australia and has not even been on the bench in the four previous Six Nations games so far.

Yet, despite having plenty of other alternatives to choose from, O’Sullivan had little hesitation in bringing the 28-year-old back into the fold.

“We could have shuffled things around by moving Simon Easterby to the other side of the scrum and bringing in Victor Costello to the blind side but the back row has worked well as a unit during the championship so far and we wanted to keep it as stable as possible,” said O’Sullivan.

“David is experienced and he is playing well, so once we had decided on the strategy it was a pretty easy decision.

“Keith Gleeson is slightly better on the ground than David but he is a better ball carrier, so on the whole, there is not a lot between them.

“Keith is a loss because he has had a great season and you don’t like to see anyone getting injured but I would not say we are weaker as a result of this change.”

O’Sullivan confirmed Geordan Murphy (ankle), John Hayes (hip) and Marcus Horan (shoulder) all failed to train yesterday but is anticipating all three will be fully fit for the weekend.