One man's pain is another man's pleasure. Leinster's Sean O'Brien has been forced to take a step outside the magic circle that is the Ireland international team because of a foot infection.
Into his place will come the wonderfully, direct and aggressive Peter O'Mahony, a Munster throwback in the Alan Quinlan mould of being a pest at the breakdown and a productive player on the ball.
"It is the benefit of being in and around the squad for four or five weeks. It is another stepping stone for him," said Ireland coach Declan Kidney.
"It is unfortunate for Sean. It would always be difficult to leave someone of his calibre out of the side. But, you take the opportunity whatever way you get it in life.
"I am sure he (Peter) is looking forward to putting down a marker. You can start talking about what you lose in Sean, but what you gain in Peter. No two players are the same. Each player has his own attributes."
O'Brien has become one of the most feared and, consequently, marked men in world rugby.
O'Mahony will not have to worry about that level of personal attention just yet. He might even sneak in under Scotland's radar.
"The benefit is Scotland, maybe, haven't analysed him as much as if he had five or six caps under his belt. He has his own nuances. If he brings those into the game, it will be helpful," stated Kidney.
O'Mahony has already played cameo roles for 21 minutes in the 42-10 home win over Italy and 14 minutes of the 17-17 draw in France. He is not exactly new to this. He is fully bedded into the process and the strategies.
However, this will be his first full cap and it is at home in the Aviva Stadium.
There are plenty of older soldiers around him to guide and direct a young man who captained the Ireland U20s and Munster in the PRO12 League during last year's World Cup.
"Once he gives it everything he has on the day, then it will be okay for us," added Kidney.
"The fact that he has captaincy experience under his belt, he knows what it is to get himself ready and get the team ready.
"Now, this is a different amphitheatre for him to go into. Certainly, he has dealt very well with everything that has been thrown at him to date."
The calm exterior does not always reflect the inner turmoil, excitement, anxiety and nervousness of a man on the brink of an international career.
"What is it they say about a swan?" said Kidney.
"It's not so much about what is happening above the water, but what is happening under the water. You would be churning a bit. If you're not churning, you shouldn't be here."
O'Mahony is here and he is ready to swim with the sharks.