The Australian, now in charge on a caretaker basis, was brought into the set-up by Andy Robinson, who quit his post following the defeat by Tonga in November, and was touched by the Englishman's gesture ahead of Scotland opening their RBS 6 Nations campaign with today's Calcutta Cup encounter.
"Andy texted us all to wish us the best," Johnson said. "He's a great rugby man and a good friend and we forget that, maybe. Of all the messages that's the one that meant the most to me . . . it's fantastic from our perspective."
Naturally Johnson would not be drawn on whether Robinson, who played for and coached England before arriving in Scottish rugby, had indicated which team he would be supporting, but Johnson cautioned all concerned to be careful about how they express their passion this afternoon.
"The passion will only get you so far," he said. "It may see you off to a good start but in the middle there's the core of the game where you have to be logical as well.
"We'll get chances and sometimes passion overrides the skill and you let yourself down, do things that you shouldn't have done and are penalised at the other end. There's a very fine line and this game will be won in that core period when the skill takes over.
"We'll get opportunities but we don't want to get so fired up that we leak points that could cost us at that period."
There is always more at stake when Scotland face England on the opening weekend since the defeated side lose not only the Calcutta Cup but also the chance to win the triple crown, the grand slam and, in all probability, the championship.
Johnson acknowledged emotions will be a major factor in the early exchanges. "People are driven when they're out on the pitch, it's a combative sport and you want people to be driven by that, you don't want them sitting back," he said.
"In the first part of the match both sides will be like that. There will be 80,000 people watching you, so if that doesn't fill you with a bit of fire I don't know what will."