Tight-head prop Euan Murray - who refuses to play on the Sabbath on religious grounds - is replaced by Edinburgh's Geoff Cross.
Cross, who scored a try against New Zealand on his last start for his country, is the only new face in the side which triumphed 34-10 over Italy earlier this month
However, despite that victory, the Dark Blues boss insists his team still have some distance to go.
Johnson said: "We have to improve on our last game and that's been our theme at training all week.
"I make no apology for saying again that we have to step up our work in the contact area. Yes, we've some talented athletes in the squad, but we have to give them the opportunities.
"It's good to see players challenging for selection - and there are a number consistently putting their hands up, which is exactly what we want to see.
"But we've kept changes to a minimum and are saying to the players: 'You've won one game. Now go out show us you can win another'."
Johnson has also recalled Dougie Hall to his squad for the Murrayfield encounter, naming him as replacement hooker after the Glasgow forward recovered from a knee injury.
Hall's Warriors team-mate, prop Jon Welsh, also wins a place on the bench, his first involvement in a Scotland matchday 23 since returning home early from last summer's tour to the South Pacific for shoulder surgery.
Alastair Kellock is also among the replacements and will become the 34th Scot to reach the landmark of 50 caps for his country if he is introduced to the action.