Rob Harley takes over from the injured Strokosch at blind-side flanker while hooker Ross Ford replaces Dougie Hall, who is named on the bench.
Italy got off to a flyer in this year's Six Nations tournament, with the impressive 23-18 win over France, and Johnson knows a tough game awaits.
"Italy's victory against France in Rome was well-deserved and certainly didn't surprise us," added Johnson.
"It will be a true Test match this weekend and it would be great to have a big vocal Murrayfield crowd supporting the boys this weekend."
Scotland:
Stuart Hogg (Glasgow Warriors); Sean Maitland (Glasgow Warriors), Sean Lamont (Glasgow Warriors), Matt Scott (Edinburgh), Tim Visser (Edinburgh); Ruaridh Jackson (Glasgow Warriors), Greig Laidlaw (Edinburgh); Ryan Grant (Glasgow Warriors), Ross Ford (Edinburgh), Euan Murray (Worcester Warriors), Richie Gray (Sale Sharks), Jim Hamilton (Gloucester), Rob Harley (Glasgow Warriors), Kelly Brown (Saracens), Johnnie Beattie (Montpellier).
Replacements:
Dougie Hall (Glasgow Warriors)/Pat MacArthur (Glasgow Warriors), Moray Low (Glasgow Warriors), Geoff Cross (Edinburgh Rugby), Alastair Kellock (Glasgow Warriors), David Denton (Edinburgh Rugby), Henry Pyrgos (Glasgow Warriors), Duncan Weir (Glasgow Warriors), Max Evans (Castres).
