Donnacha Ryan and Eoin Reddan are in the Ireland team to play Scotland at the Aviva Stadium on Saturday.
Rory Best will captain the Irish team in the absence of long term injury victim Brian O’Connell and recent loss Paul O’Connell.
Ryan replaces Munster team-mate O’Connell in the second row with Reddan in at scrum-half for Conor Murray.
Ryan and Reddan have featured as replacements in Ireland’s three games so far this season with the coach confident they can step up to the mark on Saturday.
Ulster skipper Best has shaken off a rib injury to continue as hooker and captain the team for the first time.
Best will win his 58th Test cap on Saturday to equal Keith Wood's record as Ireland's most capped hooker.
“It is a great honour to be captain and I am really looking forward to it,” said Best.
“Fitness wise I am fine. It was more precautionary having the scan and it’s comforting to know there’s nothing sinister there.”
The Ireland team to play Scotland is: Rob Kearney, Tommy Bowe, Keith Earls, Gordon D’Arcy, Andrew Trimble, Jonathan Sexton, Eoin Reddan, Cian Healy, Rory Best, Mike Ross, Donncha O’Callaghan, Donnacha Ryan, Stephen Ferris, Sean O’Brien, Jamie Heaslip.
Replacements: Sean Cronin, Tom Court, Mike McCarthy, Peter O’Mahony, Tomas O’Leary, Ronan O’Gara, Fergus McFadden.