Tadhg Beirne's familiarity with Saturday opponents will play a huge part in smoothing the second row's introduction to Six Nations rugby, according to Ireland head coach Joe Schmidt.
The Munster lock has been named alongside Leinster's James Ryan in the side for Saturday's clash with Wales at the Principality Stadium. The Kildare man spent two seasons starring for the Scarlets before moving home in a bid to wear the green jersey.
Beirne's form has been superb with his new province since his summer arrival but his international career has been a slow burn with two appearances on last year's summer tour to Australia followed by caps against Italy and the USA in November.
The Six Nations is a different beast entirely but he finally has the chance to get his teeth into the famous tournament thanks to a knee injury suffered by Ulster's Iain Henderson during the course of last week's defeat of France in Dublin.
“It's a fairly small international career so far so this is likely to be the biggest challenge for him,” said Schmidt. “He probably would have liked a bit more game time leading into it and we would love to go two weeks in a row with the same team, but we haven't been able do that with injuries.
“We've said it before that is has been a really positive challenge all Six Nations for us trying to mix and match and get that cohesion. We managed it last weekend and we have to see if we can do it now after losing Iain Henderson and Josh van der Flier.”
Beirne was a revelation with Scarlets with whom he resurrected his career after an injury-interrupted few years at the Leinster academy. His stint in Llanelli was crowned with a Guinness PRO12 title in 2017 when Munster were beaten in a Grand Final at the Aviva Stadium.
“He knows these (Welsh) players pretty well,” said Schmidt. “He played against the second rows, Adam Beard and Alun-Wyn Jones, plenty of times and he will know fellow Scarlets teammates very well. So with that combination he is as ready as we can get him at this stage.
“I know he is incredibly motivated to be as ready as he can be.”
Ryan, five years his junior, will act as senior man in the second row with Schmidt confirming that the Leinster tyro will call the lineouts in the absence of the injured Henderson and Devin Toner. The 22-year has digested that with the usual absence of fuss.
“I've learned plenty off Dev and Hendy the last season or two,” said Ryan. “It's very much a shared responsibility.”
Van der Flier's injury has re-opened the door for Sean O'Brien who was omitted from the matchday 23 against the French after a sub-par performance against Italy in round three and Schmidt spoke of a man desperate to get “back to his blockbuster best”.