The Australian spent more than four years with the senior Wales team, joining the set up as skills coach two days before Graham Henry's resignation in 2002 and working under Steve Hansen at the 2003 World Cup and with Mike Ruddock when Wales won a first Grand Slam in 27 years in 2005.
Johnson then took over the reigns as caretaker coach after Ruddock's departure in 2006, drawing one and losing two of his three games in charge in that season's Six Nations before heading back to his native Australia to join the Wallaby coaching staff.
And with a three-year stint with the Ospreys also on his CV between 2009 and 2012, Johnson can expect a warm welcome in Wales prior to handing over the Scotland straps to Clermont's Vern Cotter.
"It's not about me," said Johnson, who is about to move upstairs to become the Scottish Rugby Union's director of rugby but feels his side are due a big result before he steps aside.
"I did it for what I feel is the right fit for Scotland and I'll take up a different role and I'll enjoy that, but I'm really proud to say I've been a part of it.
"I think the last couple of weeks have been encouraging. I go back to the first weekend against Ireland, I thought we were the dominant side then, I think we played terrific rugby.
"I think there are glimpses here. Last weekend against France we showed great resolve. When you consider the penalty count that we were coming on the back of and we were playing all the rugby, to not lose your composure and really play with great intent, it says a bit about the team I think.
"I feel for the boys who couldn't finish off and we have to look at ourselves for that but sometimes the scoreboard doesn't reflect the game."
Johnson delayed naming his team yesterday due to a couple of injury concerns among his backline but Wales should know later toady exactly who they will be facing at the Millennium Stadium.
Scotland are waiting on the fitness of wings Max Evans and Tommy Seymour, while former Scarlets star Sean Lamont and Montpellier blindside Johnnie Beattie have definitely been ruled out with respective knee and ankle problems.
"We've got a few crippled. It's delayed the week but it was in the best interests of the team to provide us with the best chance to see if we can get a team out there to play," added Johnson.
"But that's life. Injuries are part of the game. We've lost a few along the way but we're no different to other teams…we're not going to sit here and wallow."