Ireland boss Andy Farrell believes Jamison Gibson-Park is developing into a "top-class international scrum-half" after selecting him ahead of Conor Murray for Sunday's clash with Scotland.
Gibson-Park has been handed his third successive Guinness Six Nations start, with the vastly-experienced Murray made to wait on the bench on his return from a two-game injury absence.
The New Zealand-born player only made his Ireland debut in October and will win the ninth cap of his fledgling international career at Murrayfield by continuing his half-back partnership with Leinster team-mate Johnny Sexton.
Head coach Farrell feels Gibson-Park is "thriving" in the number nine position for his adopted country and merits his starting role based on form and the potential rustiness of the fit-again Murray.
"Conor's not played for five weeks and Jamison has been playing really well so he deserves his start," replied Farrell when asked to explain his selection.
"He (Gibson-Park) has progressed a lot. Obviously he was new to international rugby and – although his international career has been quite short – he's had some pretty big experiences, going away to Twickenham and being involved in some big games for us.
"He's more comfortable in his role in and around the side.
"He understands what it takes now to be a top-class international scrum-half and deal with the pressures of the game and he understands the difference between the club game and the international game, so he's thriving in the role.
"He brings tempo, he brings a little bit of off the cuff type feel to the game, he plays the game that's in front of him, he's dynamic, he's got good footwork and he can ask some questions of any type of defence.
"And his game control is pretty good on the back of that so it's a nice package to have."
The inclusion of Murray – who won the first of his 88 caps in 2011 and has been sidelined with a hamstring issue – is the only personnel change to Farrell's 23 following the routine 48-10 win over Italy a fortnight ago.
Fellow Munster scrum-half Craig Casey, who impressed on debut as a replacement in Rome, is the man to miss out.
Ireland have made three alterations to their starting XV, bringing back front-row pair Cian Healy and Rob Herring and wing Keith Earls in place of benched trio Dave Kilcoyne, Ronan Kelleher and Jordan Larmour, while number eight CJ Stander will win his 50th cap.
Scotland lock Scott Cummings suggested on Thursday that Ireland's team selections are relatively predictable.
Farrell, who has handed out 13 debuts during his short tenure, was dismissive of Cummings' comments and believes competition for places among his players is fierce.
"They can say whatever they want, it's irrelevant for us," said the Englishman.
"What I know is, we're right up for this game. We know how difficult it is going to be going up to Murrayfield but our boys are really brimming for a top performance come Sunday afternoon.
"Competition for places is at its premium at the minute.
"Players are playing well and players really putting their hands up in training.
"It's a difficult one (team selection) this week but it's the right one for this game against Scotland."
Ireland, who began the competition with successive defeats to Wales and France, travel to Edinburgh seeking to continue their recent dominance over Gregor Townsend's men.
The Irish have won nine of the past 10 meetings between the countries, including two triumphs last year and success at the 2019 World Cup.
Ahead of England's visit to Dublin next weekend, Farrell is targeting consecutive victories to end a disappointing tournament to date but anticipates a stern test from the Scots, who started the Championship with a shock win at Twickenham.
"We know they are confident coming into this game, they always seem pretty confident, Scotland," said Farrell.
"Their strength is their belief. They 100 per cent believe they are on an upward curve and rightly so because we have seen some really good performances from them.
"We always find it difficult against Scotland and we're always really proud of any type of victory because we know how difficult it's always going to be – Gregor's a great coach and they've got some great players as well.
"Two wins, two good performances, that's what we're after."