Andy Farrell says Conor Murray's experience and form got him the nod to start at scrum-half over the returning Jamison Gibson-Park for Scotland.
The Munster star started the first two games in his Leinster rivals absence, before coming off the bench to replace Craig Casey in Rome and creating Mack Hansen's all-important try.
Many pundits expected Gibson-Park to come straight back into the side, but Murray stays ahead of the pack.
"Conor's a big-game player and his style of play has suited a lot of styles we've come up against throughout the years, so we expect him to be at his best," he said.
"Jamison has just come back into the group, he's not been back long. We've seen his quality in training already but Conor's playing really well and deserves to start."
With Gibson-Park, Tadhg Furlong, Johnny Sexton and Garry Ringrose, Robbie Henshaw back from injury, Farrell was asked if this was the toughest team he's had to select.
Ringrose, Sexton and Furlong are back in the starting XV, with Dan Sheehan, Murray and Peter O'Mahony also back in the side.
"Not really, no," he said.
"Form, people champing at the bit, the right balance of what fits for the starting team and what fits for the bench in terms of the energy that's going to come on is all part of the package.
"People nursing a little bit of an injury like Stu McCloskey is fit enough and if called upon is fit and well and ready to go, but at the same time he's had a bit of a niggle there. So putting your hat on and trying to balance what's right for this week and for next is key for the rest of the tournament, I feel."
Farrell has no concerns about Furlong who last played for Leinster against Ulster in early December. By Sunday, it will have been 99 days since he last saw action.
"Some players can (get up to speed) and some players can't and he's across his detail like no other," he said.
"Tadhg doesn't have to tear himself apart mentally to try and make sure that he gets up to speed because he's already figured it out.
"He's one of those that probably when he's driving the car, or sat in his room, or having a bit of food or whatever, he's probably thinking about the game anyway so when it comes to training it's all boxed off.
"He brings confidence to the team by how he prepares and that gives us confidence to know that he's ready to play.
"Tadhg's nothing to lose. He just needs to be himself, he just needs to go out there and enjoy it.
"He's enjoyed the week, he's been pretty relaxed so far, he's been great around the group. He'll build up for what's going to be a physical battle, like everyone else will, and he's nothing to lose.
"He just needs to go out there and perform the best he can for his team."
Farrell's side are on for a Grand Slam, but the Scots have plenty on their mind too with the Triple Crown there to be won on Sunday and Stuart Hogg winning his 100th cap.
“Anyone who watches the Scottish game at this moment in time, they realise they play with pace onto the ball, they’ve got a nice flow into how they galvanise the backline together the whole time. The forwards are pretty physical, the breakdown’s always very contested," Farrell said.
“They’re in good form. Again, I’m sure they’re confident going into what is a huge game for them and a massive game for us also.
"They're playing really well across the board.
"They're pretty physical in the set-piece, the carries, and the breakdown. That's all forward play.
"The forwards are setting the platform for the backs to be able to play the way they're playing as well, so at this moment in time, they're the whole package as far as they're playing. And very confident going into this game, I'm sure they are."