Chris Farrell will win his fourth Ireland cap against Scotland this Saturday, after Robbie Henshaw became the latest star hit by injury.
The Leinster midfielder was expected to pair up with Bundee Aki against the Scots, after his mixed performance at full back last weekend against England, but a dead leg has put paid to that plan.
Farrell, the Munster centre who made just one six nations appearance last year against Wales – where he started alongside Aki, steps in, with Rob Kearney starting at full back.
“Robbie just got a dead leg that hasn’t recovered sufficiently so we have to forge ahead,” said Joe Schmidt.
“It’s a pretty exciting opportunity for Chris Farrell. He stepped in once last year [against Wales] and he got man of the match.
“It was a knock on top of a knock, and some dead leg bleeding. [Henshaw] maybe could have played but if he gets another bump out of it maybe we need to make an early change. He took a part on Tuesday, didn’t train today.
“Once Garry Ringrose was ruled out it was about trying to keep a bit of continuity and cohesiveness.”
In total, Schmidt has made five changes to the XV that started against England in round one, with Ringrose, Henshaw, Devin Toner and CJ Stander ruled out through injury.
Farrell, Kearney, Quinn Roux and Seán O'Brien come in, with the latter's selection pushing Josh van der Flier on to the replacements bench, with Jack Conan earning a rare start at No 8.
Schmidt's injury list continues to grow, with the Ireland boss already planning without Tadhg Beirne, Iain Henderson, Dan Leavy, Kieran Marmion and Luke McGrath.
Keith Earls provided some rare good news after the Munster winger came through training after being replaced at half time against England with a hip injury, while Jacob Stockdale continues on the other wing.
Johnny Sexton and Conor Murray continue at half back, despite some calls for fresh blood in the form of Joey Carbery or John Cooney.
“Not many weeks go by when I don’t get a letter suggesting somebody should play here or there,” Schimdt said, “A set play or suggesting something, and that’s when we are winning.
“When you lose you can expect people to say we need Plan A, B, C, D. I’m not sure how they summarise Plan A because we have a very varied game.
“We play strong off set piece, we play a varied kicking and attack game and we try to even vary our defensive game. I’ll leave them to do their analysis and we’ll keep trying to improve.
“There has been a better edge this week. Conor and Johnny hadn't played together since Australia or played much at all. We don't volunteer any excuses. Not many men slept well on Saturday night. It probably took us until today to get a spring back in our steps.”
Ultan Dillane is on the bench as second row cover, while Dave Kilcoyne, Seán Cronin, Andrew Porter, Cooney, Carbery and Jordan Larmour complete the options available to Schmidt.