Four days ago Rhys Ruddock was not a part of Ireland's World Cup squad and yet come Sunday he may be playing a pivotal role in the quarter-final against Argentina in Cardiff.
The Leinster flanker was called into the camp on Monday as an injury replacement for Peter O'Mahony after the Munster captain was ruled out of the tournament with the knee injury picked up against France and, such is the harsh nature of competitive sport, one man's misfortune is another's opportunity.
O'Mahony's absence added to the one week ban given to Sean O'Brien yesterday means that two of Ireland's starting loose forwards need to be changed ahead of the last eight tie and Ruddock is keen to be pitched straight into the action.
His senior Ireland debut came in 2010 when he was jetted into the squad from the under-20 World Cup due to an injury sustained by John Muldoon and the suspension of Jamie Heaslip.
Similarly it was Ruddock, son of former Leinster coach Mike, who was promoted into the number seven jersey for the victory over South Africa last November when Ulster's Chris Henry suffered a mini-stroke on the morning of the game, a southern hemisphere scalp he helped to secure with a second-half try.
"I've had opportunities like this before," he said.
"I was called up from the Under-20s World Cup aged 19 and told to go put on a Test jersey.
"I really enjoyed that opportunity and the same in the autumn just gone.
"You play to play at the top level, so I'm looking forward to it and I'm ready.
"Luckily I have been around the squad for a long time. I obviously had a bit of a break where I wasn't involved, but up until then I have had a lot of exposure to the group and to the way Joe (Schmidt) coaches.
"I know all the plays and everything inside out. It hasn't been too hard, just refreshing the memory and getting the work done.
"I'm pretty much up to scratch already."
Despite needing to process his injury misfortune, O'Mahony took the time to wish Ruddock well for the duration of the tournament - and the act did not go unnoticed by the 24-year-old.
"That's the mark of the man," he said.
"He texted me to say he was delighted to hear I was coming over.
"It shows what a quality bloke he is on top of being a quality player.
"That would be the last thing on most people's minds, absolute gent.
"I had a conversation with him and wished him a speedy recovery," he added.
Ruddock's own World Cup dreams appeared to be over during the summer after he sustained a second break of his right arm.
Having already picked up a fracture when on Champions Cup duty for Leinster, he suffered the same injury when captaining Emerging Ireland against Uruguay one week before Joe Schmidt's extended panel was to be named.
Having returned for Leinster two weeks ago against Newport however, the back-rower says he is fully healed.
"I had to change my focus after my injury, I just had to work on my fitness and my skills," he explained.
"I've put plenty of time into that and I'm looking forward to it," Ruddock added.
"I feel good, I feel strong and in a good place."
I am sitting in a changing room with doubt in my head. I know I'm a good player, know I have talent but we are minutes away from walking out into a packed Thomond Park and I can't get rid of this feeling of anxiety.