Gregor Townsend admits it was difficult to leave Adam Hastings out of his Scotland team but he could not ignore Finn Russell's big-game form and the way he has re-integrated into the set-up.
Russell will make his first Guinness Six Nations appearance this year when he starts against Wales on Saturday in Scotland's final encounter.
The Racing 92 fly-half impressed off the bench as he made his return to the fold during Friday's 48-7 warm-up win over Georgia, after repairing his relationship with Townsend.
Hastings has played every game since Russell left the squad following a disciplinary issue ahead of the opener against Ireland in January but has been dropped to the bench for the game at Parc y Scarlets in Llanelli.
Exeter pair Stuart Hogg and Jonny Gray have also come in – with Duhan Van Der Merwe and Ben Toolis dropping to the bench – while Scarlets back-row forward Blade Thomson replaces the injured Matt Fagerson, who rolled his ankle against Georgia.
Townsend said: "Finn had that extra week's training and was involved in our squad last week and he's coming back into working with us again in terms of what we do in attack and defence. And you saw with his performance off the bench that he is full of confidence."
When asked if he had spoken to Hastings about his omission, Townsend said: "I do with any player who has missed out on selection. That's just the job we have to do.
"Whether the player takes on board what you say to them or not, that's up to them, but I think he has been unlucky in terms of the performances he has had during the Six Nations.
"But over the last few weeks Finn's form has been really good for his club on a consistent basis, in some high-level games, and we were certainly satisfied by his performance when he came on at the weekend, and what he has been doing in training.
"It's competition at that level for the 10 jersey and I'm sure it will continue for the next few years.
"It is difficult to leave out someone who has played a big part in the team's progress during the Six Nations. He (Hastings) has got back into form over the last two or three weeks.
"But on the flip side you have got someone who can really add something when he comes on, whether it's at 10 or 12.
"Just like on the wing, Duhan has been outstanding for Edinburgh over the past couple of seasons, really trained well with us and integrated really well into our team, and had a really good debut.
"So that's good to know we have players of a really high quality on our bench."
Hastings switched to playing inside centre when Russell came on against Georgia, but James Lang of Harlequins continues in that position alongside Chris Harris.
"The centres have worked really well in training and I thought they performed their jobs well against Georgia," Townsend said.
"It was a different sort of test match, when you get three maul tries and are maybe not tested the same way in the back line as we will likely be against Wales this week.
"But we have real confidence in Chris and James as a partnership. They get on really well, they have defended and attacked well in training. We are looking just to see them build on what they have been doing.
"Chris has been one of our best players for the past couple of seasons, and given the weather forecast, it's likely that work-rate and defence are going to be key factors in a team's success.
"In terms of other permutations, yes, we debate every position. Adam played half an hour at 12, James had picked up a dead leg, and Sam Johnson was back playing for Glasgow too. So they are in the mix, but we feel James and Chris are the best players for us."
